Carby lean it out more u think?

Discussion in '2-Stroke Engines' started by superbee, May 20, 2009.

  1. superbee

    superbee Member

    hey, im going to adjust the carb, move the clip up one notch to lean it out, but for sh*&S and grins, ill ask for opinions.

    My bike smokes alot, kinda embarassing. I know 2 strokes smoke, but this seems kinda ecsessive. That and the fact that when i run out of fuel, or I forget to turn my fuel on, when its just about out of gas, i get a BIG power increase, it revs to max rpm about as fast as a built sbc,

    Does it sound like it would help leaning it out, or not. I do run my engine pretty hard btw

  2. darwin

    darwin Well-Known Member

    With 2 stroke I dont think running lean is the answer because of a lack of oil. Are you mixing too much oil now in the mix to make it smoke alot?
  3. Shadeslay

    Shadeslay Member

    To lean is bad for the motor, even though it will likely run stronger. Some factors on deciding if you should lean your mix or adjust your clip. Are the color of your spark plug? and what is your current mix?

    You could also switch to a high grade synthetic oil which would allow you to lean the mixture more "for performance" then a conventional oil and smoke less.
  4. superbee

    superbee Member

    any recomendation on an oil brand/weight?

    And by mixture, you mean, oil to gas not actual carb mixture right?

    I wanna say this last time i put 6 oz oil with 1 gal, or a little less than 1 gallon of gas. Just cheap 5w30 penzoil oil.
  5. Mountainman

    Mountainman Active Member

    I don't think we got this right ??

    you are not putting regular oil into a 2-stroke ?? are you ??

    we are sure that you would be using 2-stroke oil ??

    as far as moving the clip one notch -- why not give it a try

    takes about 5 min at the most first time -- watch closely as the parts come out

    that little clip -- moved one notch -- can make a big difference -- sometime fun to see !!

    Last edited: May 21, 2009
  6. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Get the cheap 2 stroke premix oil from Walmart
    and use Regular gas
    Do NOT use premium

    My Grubee 2 strokes do not smoke very much even on 7 oz to a gallon
    break in mixture

    How much $8 quart oil do you want to put into a $100 engine???
    It won't make it run any better or last longer....

    Use 4 oz oil to a gallon, 32:1 for a broken in motor

    Why are you using 5w30 penzoil oil ????
    Who told you to do that?
    Last edited: May 21, 2009
  7. Pablo

    Pablo Motored Bikes Sponsor

    Your smoke probably isn't related to the rich/lean fuel air mix. (it could be, but let's set the oil issue aside for a second)

    Moving the needle may help a bit, but after a certain throttle position - the mixture is much more influenced by the main jet. The stock jet on the lowest cost generic HT engines is about 0.70mm Consider buying or making a 0.65mm jet.

    Now as for your oil, 4 stroke engine oil will work in an absolute back country pinch. But it will smoke, and by design has all kinds of additives which are not all useful in the combustion chamber. Get a good oil, mix it 32:1 and get back to us on the smoking.
  8. BSA

    BSA Guest

    My engine used to smoke alot, and i read that i needed 2 use a hotter plug. I installed one and the smoke went away and i got easier starts and the plug dont look so fouled anymore.

  9. HoughMade

    HoughMade Guest

    Don't try to solve the smoke issue by adjusting the carb until you have run enough proper 2 stroke oil at a decent ratio (if you are still breaking in, 20:1, some say 16:1, some say 24:1....I'd hit the middle) to make sure that 2 stroke oil is the only oil in there. Address only 1 issue at a time or else you will have a hard time telling when you are improving and why.

    Once you have the right oil run through, then see what's going on. If you want to adjust the carb then, fine. Do that only and observe the difference. If you want to try a different plug, change that only and see what difference there is. One thing at a time!!!

    As for leaning for performance- leaner = higher temps. good for power to an extent, but it's easy to tip over to too lean and too hot...then kiss your engine goodbye.

    It's obviously up to you, but I would prefer to run richer (not too rich, but err on the side of rich) for the sake of longevity and throttle response (usually a hair rich with react more immediately to throttle changes) rather than ultimate top end speed which will beat the engine up.
    Last edited by a moderator: May 21, 2009
  10. spad4me

    spad4me Member

    I love spad it is a cheap way to do an expensive hobby.

    You are accidentally doing spmething called a pinch test.
    I use it a lot..

    Look here

    quote from the article
    You can also use the pinch test when the engine is idleing. Pinch and hold fuel line with engine at a fast idle. Engine should speed up and die about 4 seconds. If it takes longer, your low end needle is too rich, if it takes less time or if your engine dies instantly, you are to lean and need to richen your low end needle.

    The example is on a rc engine with a tiny amount of alcohol nitro premix fuel .
    Your happy time has a much larger fuel supply but just as it is about to run out of fuel the test is the same.
    You are fine .
    It is just another tool to use to tune your engine!
    This is on a much better engine than a happytime but it still works

    I do put $8.95 dollar a quart oil in my busing happytime . The engine is on its second steel frame bicycle.
    I use 78 percent synthetic oil.
    20 percent Castor. and 2 percent Marvel mystery oil to cut the carbon.
    Since first run until forever. LOL!
    I live in the Mohave Desert, ambient temperature now over 100 degrees Fahrenheit. I need Castor to live.

    Make sure you use oil for an air cooled engine not an outboard motor.
    Last edited: May 21, 2009
  11. superbee

    superbee Member

    Wow thanks for all the replies and info guys. I feel stupid, i started out using the 2 stroke oil and after i ran out of those bottles i started using the regular oil i had in the garage because i thought i read that was fine to use. That isnt too rought on it is it because ive sure gave it a beating last couple tanks.

    Ill read through this again tonight and see what i come up with, i just ran her plum dry and ran out all my gas in the garage so i have to start fresh which is good.

    thanks all.
  12. davidsis

    davidsis Guest


    How much oil are you going to use? I use about 4oz per gallon.
  13. arceeguy

    arceeguy Active Member

    The "pinch test" works within seconds on a RC engine (no fuel bowl), but often takes a few minutes on a Bicycle engine. It is also only an indicator of idle mixture, and not mixture at WOT. The jet needle has little effect on mixture past 3/4 throttle, where mixture is primarily controlled by the main metering jet. You can fry an engine quick if the mix is too lean at the top end, even though it is slobbery rich at low/mid throttle settings.

    In any case, using 5W-30 motor oil is great for mosquito control and proper two stroke oil will reduce smoke considerably.
  14. superbee

    superbee Member

    OK, got the right oil, ran 4 oz to 1 gal.

    VERY little smoke. awsome.

    and just a little earlier, i adjusted the c-clip on the needle jet up one, so its on the second one down now, instead of 3rd.

    The mid rang seems ALOT better now, doesnt bogg out near as much. Wide open top end seemed less but if i read correctly that doesnt really have any effect on that so i assume its just because i never got the engine really that warmed up, i just took it for a quick pass is all.

    OH, i was sooo ****ed. THey had a digital screen speed trap setup on main street that takes pics if you go too fast. well THat was there the last two days, and i was like, Oh i GOT to take my bike over there and see what it tops out at, here is my chance to finally know. Ride the bike clear across town and they TOOK IT AWAY!!!!

    I but the guy woulda "LOL'D" when he seen a pic of a mountain bike on it haha.

    when it was running its peak today, judging by traffic, it seems it was anywhere between 30-40, im guessing on the low side of that. Its got expansion chamber, ngk plug, ported head.

    I really wish i would have ordered a freewheel gear, because being its a 3 day weekend, would have been the perfect opportunity to build a jackshaft. but that will have to wait a little longer.