Saturday, 28 July 2012

Tuning a Carburettor for Optimal Performance





  • Are you tired of cold starts? Need to raise the throttle everyday to get the cold engine running?
  • Does someone have the same bike with same setup as yours and are you tired of losing to him in drag races?
  • Suddenly, the fuel efficiency has reduced after a service?
  • Has the mechanic screwed up your tuning?
  • Engine gives hiccups when you open the throttle?
  • Or your bike is just missing that smooth acceleration whenever you want?
  • Or your engine overheats even if you did not race too much.

     May be the following will help you in tuning your mean machine for optimal power delivery and best fuel economy. This guide aims at tuning the fuel/air screw to give you an optimal air-fuel mixture.


    This Guide Applies To:

    All the single cylinder bikes, 2 stroke or 4 stroke having a carburetor. Tachometer is very handy and a must for a newbie or the tuning process will be very slow or painful or imperfect.


    Disclaimer: Though whatever I have written here won't do any damage to your machine. finally if you end up doing anything wrong, you must not blame me for whatever happens.


    SO LETS GET STARTED

    Warm the engine nicely. Go get a ride around the town. Drive at least for 10-15 minutes so the engine system warms up nicely or you’ll get a bad tune. Do not just leave the engine idle and start with process. I mean it. Ride the bike.

     Now searching the fuel/air screw… These screws are responsible to adjust the air-fuel ratio which forms ‘food substance’ for your engine. There is another screw which sets the idle speed of the machine. This screw is not related to pickup or mileage. It just sets the engine rpm at ’’idle’’ run. 2stroke machines have an Air screw and 4 stroke machines have a Fuel screw. I hope you note this VERY well. Air screw is located on the carb away from the engine. [ Engine - Carburettor - Air screw]
    Fuel screw is located on the carb but its near the engine. [Engine - Fuel screw - Carburetor].

    Idle screw is closely linked with the throttle cable. Idle screw can be turned by the hand. Screw driver is not essential for it. Finding these screws are very simple. If you still cannot find the air/fuel screw, ask your mechanic or I can help.

    Ok now what? Apart from the above difference I gave between Air and Fuel screw, there is one more major difference. Fuel screw turned in (clockwise) gives a lean mixture and turned out (anti-clockwise) gives a rich mixture. Air screw turned in gives a rich mixture and turned out (anti-clockwise) gives a lean mixture. Lean means more air, less fuel. Rich means more fuel, less air. This ends the basics.


    GETTING THINGS IN ACTION

     Turn the idle settings screw so that rpm reaches about 3000 rpm. Now tune the air/fuel screw to make the mixture leanest as possible. Please refer to the above whether you must turn the screw clockwise or anti clockwise.
     
     



    As you make the mixture leaner, slowly the engine RPM decreases… Go on doing this until you have put the fuel screw to the leanest possible point. At the same time, ensure that the engine does not stall, by turning the idle-screw.

    Tough huh? You’ll get used to it

    OK the engine is running and the mixture is lean. If you notice from the engine sound OR if you see the tachometer, the engine RPM will not be steady at this point. Now very slowly start turning the fuel screw anti-clockwise, 1/8th turn at a time. You will notice that the RPM increases slowly and steadily. Again, do this very very slowly.

    You’ll notice that when you have turned it to about 3-5 full revolutions, the engine RPM slowly becomes constant. It is this point that you must stop screwing more. This probably is the optimal setting for your engine.

    Further on, try turning the screw even more and more to 5-7 revolutions and you’ll notice that the engine RPM will slowly decrease. When this happens, you are just putting in a too rich mixture in your engine. At this point the engine loses all the fuel efficiency and the mixture is not optimal.

    Anyways, repeat the process about 2-3 times and get the setting which you feel is correct.

    OK the engine is humming perfectly, now what? Decrease the idle setting screw to about 1100rpm in the tachometer. When the engine slows down, just twist the throttle. The response should be crisp and quick. It should not give any hiccups! Try shutting off the engine and restarting. The engine MUST start in a single kick or self with out giving throttle. If this happens, the setting is ok. Now get a ride and you’ll notice the difference for good or bad.

    You’ll immediately notice change in the engine sound and the throttle response. Your engine can become more smooth or harsh. Another important point is, Ride and Feel. Always take a ride and get the feel of the bike in each gears, check the response and the engine sound. You’ll quickly come to know once you get the feel of the bike that you want to make the mixture rich or lean.

    It may take a few iterations before you fix a setting as permanent. Try calculating the mileage per liter and tally it with your setting and the feeling you get.



    TROUBLESHOOTING


    Here are some symptoms and their quick solutions:

    Engine dies while tuning.
    Try the process all over again. This time set the idle screw higher/faster.

    Engine gives hiccups while driving, specially while in higher gears.
    May be the mixture is too lean. Try again.

    •Engine heats up.
    The mixture is too lean or too rich. Try again.

    •Whenever I race up the engine, the rpm increases fast but very slowly comes down to idle.
    The mixture is not optimal, probably towards leaner side. Try again.

    •Too much low end torque and the engine sound is very beaty/thumpy.
    You’ll face a low mileage surely, when you drive below 40kmphr. You have tuned on the higher/richer side.

    •I have doubts or I have other problems.
    Why don’t you put in a comment?


    I hope this helps! Take care. Any comments are invited.

    147 comments:

    1. I require the assistance of this post until I take the bike for servicing later this week...

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      Replies
      1. I hope it provides the required assistance. Anyways, feel free to ask if you have some doubt :)

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    2. Garry bhaiya, for me the tuning is not rite, but the bike is as smooth and vib free as it can get. The only problem im facing is start up. If i keep the idle RPM @1.1k , the bike wont start. I f i keep it at 1.3 or something, the bikes rpm will jump to 2k rpm when the engine is hot [and idle]

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      1. Yours doesn't seem to be a tuning problem. The problem is that you're setting the Idle RPM when the engine is COLD. Set the idling to 1.1-1.2K WHEN THE ENGINE IS HOT and the problem of RPM rising to 2K will be solved. Never adjust tuning or idling RPM on a cold engine and keep your spark-plug electrodes clean. Moreover, if the bike still struggles to start in the morning (though it won't), use choke.

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    3. My engine gets overheated even on smallest rides (4-6km, and shifting gears at 5-6k rpm), Plus the mileage has dropped drastically, although the performance hasn't dropped and it runs nicely when the throttle is twisted...

      Can u tell me whats up with the engine tuning now and how should i rectify it..??

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    4. Did you fiddle with the tuning?
      Actually reduced mileage clearly tells about rich mixture. On the other hand, the overheating problem points towards exactly opposite but that might also happen because of bad setting of idle RPM.
      From what you've told, the first thought goes like you are running rich and the idle RPM needs to be set again. Share a picture of spark-plug's tip (the end which goes into the cylinder) so that we can have a better idea.

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      1. Yea.. i own a Pulsar 200NS and its CO level was more than 10, then had to take it to the svc guys and they did the afr job but always there stood a problem.. now tired of all those service men thinking to perform the tuning on my own..

        Any tips i should take care on this particular bike while tuning..
        p.s. i have never tuned any bike and this will be my first time..

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      2. As the bike is new and is under warranty, I'll say don't fiddle with it yourself. Maybe you can go to some other service station and get it rectified. You are new, the bike is new, so I won't suggest tuning it yourself.

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    5. My bike has a problem. After accelerating and letting go of the throttle, the exhaust not has quite a few loud popping noises. Is thus a carb problem?

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      Replies
      1. This can occur due to rich mixture, along with few other reasons which are not related with carb like bad timing etc.. I'll suggest first check if your air-filter is clogged and get the carb re-tuned by some experienced mechanic.

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      2. Might want to check you exhaust manifolds for any exhaust leaks try to find carbon leaks near your manifolds and replace exhaust gaskets would take 10mins if done properly

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    6. while I am tuning . should i increase my idle ? and then change the afr for optimal ?
      thanks

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      Replies
      1. Yeah! Increasing the idle helps in observing the uniformity of exhaust note better, also the movement of RPM needle becomes more prominent on increased idle. So it helps us tune better as a newbie :)

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      2. When you mean movement, you mean to say the needle moves uo and down or it just vibrates rapidly.

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    7. I hav a cb unicorn,some times its having a missing while accelerating.wht will i do.,hlp me pls

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      Replies
      1. Are you sure its missing while 'accelerating' and not when you leave the throttle (de-accelerating)?
        Well, if you're talking about engine tending to die while accelerating then it could be because of some water in carb. You'll find the overflow screw at the very bottom of the carb. Loosen it a bit and let a little petrol flow out. Try this, if it doesn't help or if you're talking about missing while 'de-accelerating' then tell me.

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      2. Get your air filter and spark plug changed it would sort u out

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    8. hello,i need a help regardin' my pulsar 200 ns.bought tis bike only two days back.my bike is giving hiccups when i try to go past 40km.i complained to the svc about tis problem.but they said when the fuel tank is filled to its brim,it'll have problem like tis n said once the petrol level goes down the bike will feel alright.also the head of the svc said that the actual capacity of the fuel tank is approx 14 ltrs.is tat true?bcoz in tech specification te capacity is specified as 12ltrs only.So fillin' it to te brim has actually caused tis problem(ie 14 ltrs)..?very confused,pls help me in this.thank you

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      Replies
      1. hi rakesh, i am not an expert myself but have been doing some online research on carburetors. Regarding your problem, i think it is related to the main and pilot jets in the carburetor. Air/fuel ratio, if incorrectly set, will cause rough engine sounds through the whole range of rpm (low to high) and not only in high rpm. Try to either clean your carburetor jets, and check the needle and float. It seems like the pilot and main jets are not the correct size.

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    9. hi! So if i turn the screw anti clockwise and the idling goes higher i should keep turning till it doesnt go any higher?

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      1. You need to observe the exhaust note. It should be beating uniformly at the optimal tune (or you can choose to observe the tachometer instead. The needle should be steady at optimal tune).

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    10. ok... this is what i did and my bike is great! I took idling up then i screwed the screw in till the bike almost dies then i slowly turned the screw out.... i could hear the revs going up and i kept turning... the revs kept going higher... and then on a spot the revs stayed the same for about 1/4 of a turn then the revs dropped.... i then screwed it in 1/4 where the revs was the highest point..... is this right? Bike runs well and sounds nice ....

      ReplyDelete
      Replies
      1. If the throttle response is crisp and mileage is good enough, then its all good for you. Glad that it helped you. Keep visiting!

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    11. I think so I have done it. But I have set 1.2 rpm and when I restart the bike and give sudden throttle it cuts the bike. What should I do.

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      Replies
      1. You must have set the RPM while the engine was cold. Ride the bike for a few 2-3 miles and then set it.

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    12. what is the valve clearance value of both inlet/exhaust in Apache 150cc bike...

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    13. Can anyone help on finding my fuel/air screw? Iv found the idle screw. I have a yamaha fazer 6 2008. Help appreciated

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    14. Hello Every One...!!!
      I purchased pulsar 135 ls recently it used to run smooth and the pickup was great my bike use to reach 90km/h at very ease. But after 1st Service my valve and tappet are making noise bike is taking much more time to conquer speed of 90kmph Poor Pickup ,Engine giving hiccups ,Whenever I race up the engine, the rpm increases fast but very slowly comes down to idle. engine heats ups very quick
      my bike has a auto choke but still it dies in the morning...??
      my odometer shows only 534 km
      and my bike is running like im using a old bike
      tell me...???
      suggest me...???
      what to do now...???
      is there any thing i have to do with my carb..??
      or RPM
      or valve or tappet...???

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    15. From what you've mentioned, looks like you're running a lean mix (less fuel and more air).
      Take it to SVC and have it set correctly and it will be back to how it was !

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    16. Hi Gaurav ! I want to tune my karima r carb as fuel economy has drop after 6th servc please can u help me locate the fuel and air screws. Thnx.

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    17. hi gaurav i have a hero impulse 150 and i am going to participate in race (city local ) and my problem is the bike hicupps in first gear its reduced the power of engine and break the speed (dirt race required more power in first gear) we bored cylinder and fixed big dia piston (100 no) for better pick-up please suggest me something for better result if possible ASAP (suggest me also for exhaust pipe )

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      Replies
      1. As you've increased the capacity, I'd say get an air filter which could feed more air into the engine. Aftermarket free flow filters might help you. Though I usually don't recommend those to people as it reduces the life span of engine but as you're already into racing and modifications, I think it won't hurt you much. Get an aftermarket free flow filter and tune the AFR according to that. You may or may not require upjetting.

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    18. hi, my bike is 4 stroke, initially i turned-in the fuel screw fully in but 1/4 less, so that the engine runs and i set the idle rpm to 3000rpm. Now slowly i anti clockwise i screwed-out the fuel screw, at 2-3 complete anticlockwise turn-out--the engine rpm is idle. Further again i turn-out fuel screw out to 3-6 revolution-the engine rpm increase slowly. Now after 6 revolution of fuel screw further turn-out 6-7, the engine rpm decrease. Now where should i set the fuel screw-between 2-3 revolution i.e 2.5 or at 6 revolution.

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      Replies
      1. Set it at the first balance point you get which is 2.5 in your case. Ride it for some time. If the throttle response is crisp and the spark plug tip is brown (check after 50-100 kms.) then it confirms your setting is optimum.

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    19. Hi my dirt bike wants to die when I give it gas to fast what is wrong?

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      Replies
      1. You're running the rich. Turn the airfuel ratuo to the leaner side. Tge fuel supply is more with less air so its having trouble breathing when you go hard on gas. Reduce the fuel supply.

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      2. how would i find the air fuel mixture screw on a 99 xr100r i cant seem to find it

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      3. do i have to warm the bike up first to?

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      4. Yes, you have to warm it up first. And sorry I can't help you with the location of AFR screw on your bike as we don't have that bike here in India. Hope you will find it out in service manual.

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    20. Hi, I have CB Unicorn 5400 kms done. after giving to service i could feel a different engine smoothness. if i twist the throttle suddnly when i am abouve 60kmph, i feel there is no response(like how if the fuel is about to be empty) and aboove 60 it will take lot of time to reach 80.. then i thought of adjusting carb as per the steps given here. i did it and then the performance was mind blowing !! no vibration, crisp acceleration and could reach 100 in some seconds.. but when i observed, i felt engine heats up bit quickly even if i ride slowly.
      i will explain how i carried out the tuning step..
      1. Engine was warm actually. i had travelled around 15 kms before doing this setting
      2. I turned the idle screw to 3000 rpm.
      3 then turned the screw to leaner side. (fully clockwise till the end)
      4 Then started turning anti-clockwise slowly. (around 2.5 full revolutions)
      5 turned the idle screw back to 1100 rpm.

      Is this method proper?
      Observations while setting carb :
      1 felt engine was heating a lot.(cud feel a lil smell whn i went very near to engine)
      2 when turning anti clockwise from leanest point, after about 2 full revolutions, engine rpm was about 3250 rpm and was constant. i left the setting at 2.5 revolutions) and then turned the idle screm from 3.2 k rpm to 1.1k rpm.

      was this the exact method of tuning or once i set idle to 3k rpm, do i ahve to set it to 1.1k when i set the leanest point ?

      ReplyDelete
      Replies
      1. If tge bike is overheating then it means you are running lean. The method you described above is the right method to tune and if the observation of uniform exhaust note (optimum point while tuning) is correct, then it shouldn't be a problem. Is your throttle response crisp? Does it get started easily in the morning? If answer to both questions is yes, then try making it just 1/8th turn richer (anticlockwise) and then adjust the idling to whatever idle RPM is recommended for Unicorn. Usually ithe recommended idling is 1.1-1.4 only and shouldn't make much diff between this range.

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      2. If tge bike is overheating then it means you are running lean. The method you described above is the right method to tune and if the observation of uniform exhaust note (optimum point while tuning) is correct, then it shouldn't be a problem. Is your throttle response crisp? Does it get started easily in the morning? If answer to both questions is yes, then try making it just 1/8th turn richer (anticlockwise) and then adjust the idling to whatever idle RPM is recommended for Unicorn. Usually ithe recommended idling is 1.1-1.4 only and shouldn't make much diff between this range.

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      3. So you mean to say that i neednt set the idle screw back to 1.1k rpm once i turn the screw clockwise to the leanest point..
        i asked this again because the rpm goes above 3250 when i turn anticlockwise above 2 full revolutions and i felt may be this is the reason for heating

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      4. And one more thing what i observed is that how much ever i turn anti clockwise, the rpm dint come down.. til around 9+ full turns.

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      5. No, I didn't mean that. You sure need to bring it back to 1.1 using Idling screw after you make adjustment with the AFR screw.

        And don't see it the way that it will come down or go up on turning anti-clockwise. What you need to notice is uniform exhaust note pattern. That is where you're gonna get the optimum air-fuel mixture.

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    21. This comment has been removed by the author.

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    22. Greetings All,

      Posting after a long time owing to a new job and other reasons

      completed 10k on odo - ALL STOCK

      Lately, experiencing a flat spot b/w 5-6k rpm

      SVC rep cleaned the air filter, all plugs, drained fuel from carb and adjusted AFR but no good.

      tried adjusting AFR on my own..from 2 turns out to 4 turns out from fully turned in screw position...but no luck

      bike avg is 46 kmpl at 2 turns out and 35 kmpl at 4 turns out (tank full to full) but didnt get rid of flat spot

      Just cant cruise at 75-85 kmph which happens b/w 5-6k rpm

      bike still pulls great post 7-7.5k and reaches 142 odd speedo indicated

      have re-fueled from a different petrol stn but didnt help either

      SVC advises against opening the carb and checking

      Any pointers suggestions at all?

      Best
      Abhishek

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      Replies
      1. Sounds like diaphragm issue. Get it replaced, it should solve your issue.

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    23. Well can you please upload a video for the same with gixxer 155 so that it will be more easy to take the reference to.

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    24. This comment has been removed by the author.

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    25. Hi, My Hunk bike has morning start problem from atleast 3 yrs. It starts only on full Choke, then I have to decrease it slowly to end(it takes approx. 3 min.in winter & 40 sec. In summer). Meanwhile using acceleration stops engine.
      No other problems except little vibration & low average.
      Pls help... thnx.

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    26. Feels some hiccups in my 220 while.deaccelerating.. ..when the bike is in a steep hill..

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    27. Feels some hiccups in my 220 while.deaccelerating.. ..when the bike is in a steep hill..

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    28. Royal Enfield Classic 350

      please need your suggestions and advantages for bike

      1.will my bike will cross more than 120km speed

      2.will it give more mileage

      3.will it reduces vibration

      4.will it reach 0-100km in short time as soon as possible

      5.more advantage I need from you admin

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    29. Will it increase pick up speed at initial moving

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    30. This comment has been removed by the author.

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    31. Hi, i have derbi terra 125 and i put new muffler on. I rejjeted it from 100# to 110# main jet. Before, it was choking a little at 1/4 throttle. Now it chokes from 8000 to 9000rmp (max is 10700). It sounds like it is grinding something inside the engine but it isn't. Power loss is very noticeable. It's struggling to pass those rpms and after that it's fine. I tried to tune the carb following another tut (haven't tried this one sorry). I managed to reduce choking by turning my fuel screw out (4stroke) but still problem is there... Help me please!

      Leo

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    32. hey buddy help needed:
      i have a 125w welsh pit bike i got it as a non starter i ivestigated and found the stator to be broke i held the broken bit in place and started the bike and i idled and had throttle response so i replaced the stator with a £10 stator from ebay.
      but now after replacing i started the bike and it will only start on full throttle and will not idle and full throttle is giving be about 1200-1800 rpm with any ideas would be a great help thanks

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    33. Hello gaurav
      I own pulsar 220dtsi 2014 ..completed 14 k on odo ..
      Having problem of bike giving jerks while accelerating past 4k rpm and constantly after 4k at 5th gear ...
      Checked for water ...retuned the carb from mechanic but it didn't help ...svc guys saying diaphragm of carbeurator need to be replaced ...
      Please suggest some solution ..

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    34. Hello gaurav
      I own pulsar 220dtsi 2014 ..completed 14 k on odo ..
      Having problem of bike giving jerks while accelerating past 4k rpm and constantly after 4k at 5th gear ...
      Checked for water ...retuned the carb from mechanic but it didn't help ...svc guys saying diaphragm of carbeurator need to be replaced ...
      Please suggest some solution ..

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    35. hello
      i own a new mahindra centuro and it has completed 7500km.from day 1 it has not given me mileage above 45km/l i complained it to service center and they have changed my carburetor and suddenly after that my mileage increased to 75km/l in city but after 2-3 days it dropped out to 42-45km/l in highways(nh2).please someone help me.

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    36. hi i have suzuki fiero 2002 model i tuned it but still i am not getting proper milage

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    37. hi i have suzuki fiero 2002 model i tuned it but still i am not getting proper milage

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    38. Hi ! You really have nice blog.
      I have a honda shine 125cc bike. it vibrates after 50kmph. Also maximum speed for 3rd gear is 25-30 kmph after that it startsvibrating. so usually most of time i drive my bike at 4th gear. The honda service man says it normal for honda shine. I have driven super splender 125cc but there has no problem like this. I really need your opinion is this normal for honda shine?

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    39. Hey Gaurav,
      I do have few issues with my carb.
      1) When i go for a ride and park my bike back home i see a few drops of fuel on the overflow pipe. I got my bike carb cleaned from the SVC here too but now after the cleaning looks like its got even worse with more fuel coming out. What do i do for this problem?
      2) When i ride my bike and i am around 70-75kmph between that speed around 70-71 i am facing a slight missing between that speed only otherwise its normal.
      Not sure if that issue is also because of carb. Tapet adjustment was also done recently and there s no noise of tappet.

      I hope you can help me out and give me the best solution cause the SVC guys are pathetic and i do not know how these mechanics are hired with no knowledge of bikes.
      Infact over a period of time with some or other issue arising in bike i m myself learning how 2 sort it out than the mechanics :D

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      Replies
      1. Check the carburetor jets, needle and float.

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    40. If the 1976 KZ750 standard idle in the manual says 950-1050 RPM's, and my bike stalls at that but works fine at 1400-1500, plus the fact that the carbs on it were said to be abominable (1978 Cycle Magazine) then is it a false hope to reach a 950 idle?

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    41. Nice and helpful article. I am facing a problem with my scooty pep plus. After running for around 6-7 KM as I brake to stop the scotter dies down, then I have to kick start it, it will fail to start with button. Please help

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    42. Hi
      I have Honda shine completed 150000 kms in 8 years without any failure.
      Till date I scheduled it regular service between 2000 km
      Earlier from speed 50 to 100 km it was going very smoothly on top gear but from last one year bike fail to deliver same and same I have pointed out to scv but they haven't resolved it.
      From last few months another problem I am facing is bike keep accelerate higher on ideal post ion after long run till I won't switch it off.

      How to understand rpm for those bike which don't have tachometer for fuel setting

      ReplyDelete
      Replies
      1. change the bike as i am suffering from the date of purchased

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    43. Hii I have Yamaha fz bike of 2010 model and I am suffering from milage of 25kmpl.how could I increase my milage please suggest and what could be the. Problem

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      Replies
      1. For milage many factors need to maintain.... Regular service,riding style, carburetor Fine tunin.... You won't believe my Honda shine gives 80 kmpl on speed of 40-50 kmph...My Jawa 250 cc gives 45kmpl on speed of 40-50 kmph....

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    44. Hello i have a suzuki gixxer 155 My bike hichups down when I raise my throttle everytime but after 15 to 20 minutes it stops and more after 15 to 20 minutes it starts. What should I do plzz provide help

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    45. Hi G..I have pulsar 150 2006 model...there is raising noise while shifting gear even though zero acceleration position and with closeed clutch and my idle is almost zero but my idle rmp shows 1.3 to 1.5k... Milage is also low... And has some tik tik noise from engine even the tappet screws of both inlet and exaust valves are chaged..
      what to do Gi....guide me plz

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    46. hi I have pulsar 135ls and the problem I have with it is that I when I start the bike it has idle but it's not taking throttle, I did adjusted the a/f mixture but no luck when I give it a gas the engine stops with "burrrrb" sound like its over feed. but like I said I did adjusted the a/f mixture from 2.5 to 4.5 and the adjiusted the idle but still no luck..
      hope you can help me with it thanks in advance

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    47. my bike not moving smoth give me any tips

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    48. My bike goes off when i release accelerator . what is prolem and its solution .please tell me.

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    49. My bike got screwed up when i tried this . ans i assure you i did it safely.
      best way is to do this under mechanic supervisoin, my carb almost got damaged.

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    50. Hey. After my bike is properly warmed up, my bike noticeably jerks when I twist the throttle. Also there is a noticeable flat spot at higher rpm when the bike just doesn't accelerate properly till 8k, after which it picks up like crazy. Very bad mileage as well, like 27-28 kmpl. This is a Pulsar 200 AS. I'm going to try and tune the bike myself, but I'd like to hear your thoughts as to why this is happening.

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    51. I have a 02 r6 with a 4 barrel carb how should I tune it? Should I tune carb 1 then sync the other 3 or all 4 at once cause this has been a huge pain. First lean then rich now a little of both and the screw are hard to access can't adjust with bike running as I have to remove gas tank but carb 1 is easy access while running and tank on

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    52. I have a problem. Whichever lean or rich mixture i put my a/f screw, my bike still has throttling problems. The idling is okay at startup, it won't die if the throttle is untouch. But if I slowly twist the throtlle the carb feels like drowning and dies. But If i twist the throttle a little faster or fast, it wont die . There is an rpm point where my engine dies or feel drowning even at warmed up or even when running. something like 1600-2000 rpm is not stable for by carb. Remember that I completely did your instructions but still don't work. My bike is the 2016 Suzuki Gixxer 150 (154.9cc) And the carb is problematic i guess, i tried different fuel brand but still never worked.

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    53. very nice and easy trick to set your bike carburetor.

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    54. hi i have a 1998 r1
      it starts and ticks over fine its when you take choke of then the problem starts, its as if its misfiring< i have put new spark plugs new coils new rectifier, and new stator, and battery
      when im at say 3/4000 rpm its as if the fuel is not going in smoothly but soon as i put choke on at same revs bingo its a new bike
      have used sea foam to clean carb mixed with petrol ant ideas
      geoff

      ReplyDelete
    55. I got a modified honda wave 125cc but I rebore it up and it is now a 150cc engine, i have installed a 30mm SPD flatside carburetor..first to third gear rides so tough when I launch on first gear the bike always do wheelies even on second and third gear but when I hit fourth gear a lot of hiccups occur..Ive tried setting the pilot jet and the air jet several times Ive got combinations of 110-40, 125-45 and 111.08-41.08 the last setting I did was good never hiccups through all gears but a rough idle, great start at mornings but when all warmed up idle become rough but responsive and aggressive when I twist the throttle..is there any problem whit that? Since when i did some cam grinding i set both cam lobes on high lobe setting the engine produces more power with a semi rough idle..how do you think i can solve this problems?

      ReplyDelete
    56. Hi...I have a hero honda hunk...it starts to hiccup after I ride it fast for a while....engine dies when put to gear and accelerate....donno why...can u pls help

      ReplyDelete
    57. my pulser gives 35 mileage how can I increase?

      ReplyDelete
    58. All Carburatores of four stroke is same
      As i have cb shine 2014 model

      ReplyDelete
    59. Hi there .
      I have my horse my all time favourite a bajaj Cheetak 1993.
      Recently I have changed the carburetor ie. Honda type(spaco make). I have problems related to setting of the fuel consumption.
      Last 2 months back it was of with an average of 44/45 per liter.
      Now its giving an average of 33/34 kmpl. Since it has drastically reduced I need your guidance and expert advice. to retain back the average.

      ReplyDelete
    60. Hey, very nice site. I came across this on Google, and I am stoked that I did. I will definitely be coming back here more often. Wish I could add to the conversation and bring a bit more to the table, but am just taking in as much info as I can at the moment. Thanks for sharing.
      Scooty Pep Plus for Handicapped

      Keep Posting:)

      ReplyDelete
    61. Hey, very nice site. I came across this on Google, and I am stoked that I did. I will definitely be coming back here more often. Wish I could add to the conversation and bring a bit more to the table, but am just taking in as much info as I can at the moment. Thanks for sharing.
      Scooty Pep Plus for Handicapped
      Keep Posting:)

      ReplyDelete
    62. On cbz Xtreme...after screwing in and then screwing out...slowly...when I find that tacho is not increasing...and as I am not sure how much I have screwed out after constant...I go further to screw in untill the point before rpm starts to drop...!! Find engine, start etc smooth without hiccups..😊 want to know whether the method is ok or not ??

      ReplyDelete
    63. On cbz Xtreme...after screwing in and then screwing out...slowly...when I find that tacho is not increasing...and as I am not sure how much I have screwed out after constant...I go further to screw in untill the point before rpm starts to drop...!! Find engine, start etc smooth without hiccups..😊 want to know whether the method is ok or not ??

      ReplyDelete
    64. i have recently changed the carb of my fz 16 but there is some tunning issue my mike misses alot on speed of 50 55 some time petrol comes out of carb. does any1 know any mechanic to help me over that carburator issue service centre mechanic are good for nothing.

      ReplyDelete
    65. i have recently changed the carb of my fz 16 but there is some tunning issue my mike misses alot on speed of 50 55 some time petrol comes out of carb. does any1 know any mechanic to help me over that carburator issue service centre mechanic are good for nothing.

      ReplyDelete
    66. Hi,
      I bought Honda Unicorn 2007 model few days back and this bike was sitting idle for few months with the previous owner.. as soon I got I felt the bike need some servicing as when you rev up it comes down (deaccelerate) slowly.. and this causes high revs while changing gears..
      I have good hands on in mechanical stuff so I opened up carb and saw lot of crud sitting in float bowl.. used carb cleaner and gave complere clean in n out.. sprayed from jets n all holes.. choke piston was dirty so cleaned it too.. re-assembled and started tuning.. I tuned hopefully good but still see the revving issues.. also when bike is hot it revs very high on its own around 4-5 rpm.. this is same thing happening from day one I bought the bike.. after a lot of diagnostics I unplugged Throttle position sensor (3 wired sensor on throttle butterfly) and the reving stopped...
      I checked sensor with multimeter and its fine...

      Now my question is :
      1. Where does this TPS connects in unicorn? In car I understand it goes to ECU which in turns adjust fuel injectors.. but in motorcycle I dont know where does it goes..

      2. Running bike without sensor gives sudden pickup issues while over taking.. with sensor bike has good pickup.. means surely its controlling fuel & air feeding to carb... but nowhere i can see any elctronic adjustments / relays or coils near carb or air filter..

      3. Can some one source wiring diagram of Honda unicorn or atleast service manual so that I can see function of TPS in two wheelers.

      Please help me out guys.. has anyone faced such issues earlier?

      ReplyDelete
    67. The variety of valves available to employ on a project is staggering, and usually the choice of which to use is based on the technical application, the ease of use by operators and maintenance personnel, and the cost. Check out this trupply

      Oilfield Ball Valve

      ReplyDelete
    68. Hi All,
      I have purchased my Bajaj pulsar AS 200 in last year , it is 10 months old. And i am facing problem with the fuel injection.
      When i am speeding my bike quickly then it will stuck like my bike goes to the reserve(But Tank were full).
      It is very big issue with my bike. Please suggest me what to do in this condition.

      ReplyDelete
    69. Dear friends if any one has a clear idea as to what should be done to restore a good fuel average on my problem state/posted on 24 July kindly guide me or post your comments or reply me by mail on daddimullanm@gmail.com
      Regards.

      ReplyDelete
    70. My bike is tvs flame, i have bore the engine due to a case of rod.. after that now i feel it done more pickup before the engine bore. as my knowledge after reboring an engine it gives more power due to the capalcity of bore.. but it doesn't happen. What should i do for this??

      ReplyDelete
    71. Hi My bike is pulsar 200 2007 model.
      Can anyone guide me on this problem:
      After riding my bike for 4 to 5 kilometres the idle rpm automatically increases. After this it becomes difficult for me to put it on first gear.
      But if i allow the bike to cool for 1 hr the idle rpm lessens and problem dissapears.

      ReplyDelete
      Replies
      1. As my knowledge it's just a small problem in carburator tuning.. adjust the carburator correctly.

        Delete
    72. Yours doesn't seem to be a tuning problem. The problem is that you're setting the Idle RPM when the engine is COLD.

      https://dubaiposter.com/

      ReplyDelete
    73. I have a bajaj caliber. its engine heats up in just 2-3km ride & getting a very bad mileage (50km-60km) in optimal riding. Please help me..

      ReplyDelete
    74. Hey,Gaurav I have a Tvs Fiero F2I have recently changed the jet of my carburetor but after that i am facing the problem of jerking in bigger gears and full throttle.I even tried pulling the choke and riding tu see if the fuel supply is proper or not but the problem still exists.Can you tell what problem could it be ?

      ReplyDelete
    75. This comment has been removed by the author.

      ReplyDelete
    76. thanx for help..very very helpful post..i tuned according to ur instruction and my engine is soft and rpm on 1100rpm and just made top speed 138kmph..peace :D

      ReplyDelete
    77. i have honda stunner.the accelerator increase automatically after some time of driving, pls guide so that i can tell mechanic to rectify.

      ReplyDelete
    78. I have Bajaj discover 100T there is no tachometer.. how can I connect a tachometer to this bike if I brought it separately

      ReplyDelete
    79. Dear All..
      I have Bajaj 135 FS , there is the problem while driving its gets Air lock like driving time after 40 km speed its gets locked and speed gets reduced i cant drive continuously its gets locked .. kindly advice

      ReplyDelete
    80. Hello everyone, I have a honda dio and I am currently getting approximately milage of 120-130km in a full tank thats like 20-30 Kmpl and this is my biggest problem I am facing right now, please help me and if possible can someone guide me on this, I have tried both the sides of the fuel to air raito screw as I was really confused which screw it was.

      ReplyDelete
    81. Your thinking toward the respective issue is awesome also the idea behind the blog is very interesting which would bring a new evolution in respective field. Thanks for sharing.
      Bike Spa Services in Mumbai
      Bike Cleaning Services at Doorstep in Mumbai

      ReplyDelete
    82. This blog explains the details of most popular technological details. This helps to learn about what are all the different method is there. And the working methods all of that are explained here.
      Back to original

      ReplyDelete
    83. Hi bro, I did this on my 1981 year RE bike. I got 2 complete revs in factory setting and I changed the revs to 1 and half by checking 4 times. Now, my bike performance increased. I have done this on 24th Dec and performance is good and went for a ride of 50kms. On 25th Dec I didn't ride my bike and while I starting my bike on Dec 26th, It's not starting. I turned the idle screw click-wise for acceleration and it started but, when ever I'm decelerating it is stopping. Smoke also coming more while accelerating. Previously, my bike is good with no defects. Could you help me ASAP?

      ReplyDelete
    84. What is wrong with my 125cc if it cant even get to 85km per hour

      ReplyDelete
    85. Hi I am using pulsar as200 but problem is throttle response not good when I give acceleration 7 thousand rpm reach means suddenly power loss pickup not coming after few second power was releasing I fell that again I close the throttle and again I give acceleration power lose I don't know what to do already I done valve clearance and tapped nut adjust done but problem not solve plz help me what I do

      ReplyDelete
    86. Is the same process needs to be done on a non geared two wheeler while upgrading your air filter ?

      ReplyDelete
    87. Hello Gaurav..

      I purchased new Honda Shine Sp, after few months it met with an accident. I claimed insurance and it was again looking like new beast. Before repairing its top speed was 110 Kmph, but now it not even crossing 100 Kmph. I'm sure that there was no problem in engine after accident but the acceleration wire was changed. Tell me solution so that I achieve my old top speed again.

      Thanx

      ReplyDelete
      Replies
      1. Top speed doesn't just depend on tuning, or a matter of fact, not just engine. Your post suggests that it can be literally anything that could be wrong after the accidental repair. Get your bike checked in person by a skilled mechanic, that would need physical inspection.

        Moreover, I'd just add a little unwanted advice. Do not stretch your bike to its limits. 100kmph itself is more than sane speed for Shine.

        Delete
    88. Dear Gaurav,
      Currently i'm facing an issue with my bike ( BAJAJ DISCOVER 135 ),the problem is when i stands my bike over side stand petrol becomes dripping through the overflow pipe underneath the carburettor and rpm of my bike not remains constant so i need your kind help in this ragard.

      ReplyDelete
    89. Dear Gaurav,
      Currently i'm facing an issue with my bike ( BAJAJ DISCOVER 135 ),the problem is when i stands my bike over side stand petrol becomes dripping through the overflow pipe underneath the carburettor and rpm of my bike not remains constant so i need your kind help in this ragard.

      ReplyDelete
      Replies
      1. Unscrew the overflow screw, let some 50-100ml petrol drain out and tighten the screw back making sure it's not leaking. Get it cleaned in case the problem persists.

        Delete
    90. Hi,
      I own a jawa 250. Recently v have Re bored the engine. Normally when i drive in traffic it over heats and turns off. Also pickup drops drastically Why is this happenning I hav driven it about 500 km till date

      ReplyDelete
    91. Hi,
      I own a jawa 250. Recently v have Re bored the engine. Normally when i drive in traffic it over heats and turns off. Also pickup drops drastically Why is this happenning I hav driven it about 500 km till date

      ReplyDelete
    92. My passion plus missing when drop accilator and in morning start in one kick but when give throtle it stop.means i have take choke and race 1 or 2 minutes then
      I able to use.

      Kindly give suggestion

      ReplyDelete
    93. Hi i own hero ignitor i got messed with tuning and referred 2 mechanics after that milage reduced to 45kmpl i was getting 55kmpl minimum but now too low milage help me with this please

      ReplyDelete
    94. I've got a Yamaha Zuma 50cc when I accelerate above half throttle the scooter bogs down heaps and can't go more than 40kmh but if I bring a bit of choke on it goes fine. Does that mean it's running lean or would there be a bit of a block in the fuel line, it doesn't do it when its got 3/4 to full tank of fuel.
      Cheers

      ReplyDelete
    95. I 've a hero Honda passion plus...the bike starts moving even before aacelerator is rised...how to get rid of that

      ReplyDelete
    96. Has anyone else mentioned the mass airflow sensor? This electronic sensor measures the amount of air and fuel so there is an accurate mixture. For most vehicles, the mass airflow sensor connects to the check engine light so drivers are aware if there is a problem causing the engine to take in improper fuel to air ratios.

      ReplyDelete
    97. Hi
      I have CB unicorn 160 ...I have done carb tune as per the basics ( tune is 2.1/4 turns)..now I observed that..my bike works good and effortless sooth performance at high end ( 80-90-100kmhp)....dont know it is because of lean mixture or rich mixture.
      But the matter is bike is not smooth when I ride in low end or middle end (30-40-60kmph). engine sounds little hard not so smooth while accelerating. not giving smooth rev at initial pik-up.What to do
      now I am unable to find that this is lean mixture or lean mixture...how to get optimal mixture for both rides at low end and high end..

      ReplyDelete
    98. This comment has been removed by the author.

      ReplyDelete
    99. I think i have adjusted drain screw of my carburater
      Now i dont know how to close or open it.
      I have dream yuga and i also don't know my carburater have air screw or fuel screw.

      ReplyDelete
    100. Hi sir,

      I have honda shine 2012 model,

      Issue is ,Honda authorized service center guy has change lifter assembly for timing chain, after that work, one issue arised, is that , whenever i start bike, its doesn't match with the throttle acceleration like (petrol is near to empty ) for some distance like 1 km, after then speed matches with throttle up , this issue arise on every time i start bike after say interval of 30 min or more .

      can anyone tell what is the issue???? i have service the bike and they have cleaned arifilter ,sparkplug, carburetor etc..

      await for reply

      ReplyDelete
    101. Every time when you start your bike pull chock and use kick starter. hold chock for one at least 40 sec..until you feel good acceleration and then proceed your ride....if this doesn't help write me back.

      ReplyDelete
    102. I am setting the idle to 3000 rpm but when i try to get a lean mix the rpm goes up until its seated at 4000 rpm. Any idea what I might be doing wrong?

      ReplyDelete
    103. You have two stroke bike or four stroke ...if four stroke...turn your fuel mixer screw anticlockwise for rich mixture and clockwise for lean....Your rpm is increasing up to 4000..that means you are making it rich

      ReplyDelete
    104. Is this still active for comments?

      Thank you for the tips! They helped me to undestand about carburetor....



      Mine is a hero scooty plesure.... after 4th service it's consuming petrole more than i expected... almost 25km for a 1L.


      Can you tell me how can i fix this? (I am not sure about the guy working in the service station..... and i couldn't find a article regarding to exact byk!) Thanks

      ReplyDelete
    105. LOKESH ENTERPRISES are considered as the noteworthy manufacturer and supplier of a comprehensive assortment of Automotive Products. The offered range comprises of Cable Assembly, Accelerator Cable, Bonnet Cable, Clutch Cable, D Compressor Cable, Stop Cable, Handbrake Cable, Diesel Pipe, Brake Pipe and Brake Hose etc VIEW MORE :- Car seat covers

      ReplyDelete
    106. my frnd's suzuki gixxer naked hav a problem
      while in 4 th gear missing at 50 to 60 km/h
      while in 5 th gear missing at 60 above but coming to steady while trottle is put on hold

      ReplyDelete
    107. i have a sccoty streak, soon after a year of purchase it started showing problems.Scooty would start perfectly but after going few kms,there is airlock and accelaration problem occuring.At first the mechanics told that carburetor is causing problem and cleaned the carb. But issue again reamained and i had to change the carb. still there is no end to this problem.what may be the issue?? really frustrated since last three years.

      ReplyDelete
    108. why my carb has a slow response when i twist the throrle in 4th gear?

      ReplyDelete
    109. This comment has been removed by the author.

      ReplyDelete
    110. Very useful blog that have shared. Please share more details about it. Thanks.Honda bike showroom in tambaram

      ReplyDelete
    111. I have Suzuki gixxer 155, mileage is 26-30, srweing in increasing the rpm and vice versa of carburetor, plz help

      ReplyDelete
    112. I have Honda activa recently I serviced and later found my engine tuning was screwed up, resulted in sudden engine off while waiting in traffic signal. With frustration I tried to tune my engine on my own with the help your post and some videos.

      Now here's my problem my engine is giving more mileage than before and I am worried it may be bad.

      My previous mileage was 45 kmpl now it's like 55 kmpl.

      You said to keep the fuel screw in 3-5 revolution from least position but I've place it only half revolution from the least position in clockwise. Because that's where the engine sounded better.

      My scooter running smoothly other before and no problem so far. But I am worried that maybe tuning the engine give more mileage may damage or overheat it. So please give me advice.
      Thank you.

      ReplyDelete
    113. hi i have got apache 200 I just need ti check if there is some problem with the pickup coz when I pull the throttle there is always a delay in pickup. just help me if engine tuning will help or not.

      ReplyDelete