Two Stroke Motocross
Two Stroke Motocross Forum => Technical => Topic started by: Suzuki 2strokin on February 15, 2011, 06:30:12 PM
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Title basically says it all. Engine was idleing for a short period of time and the all of a sudden shut off? opened up the carb and the needle seat wasnt connected to the float like it was supposed to be. what could cause this? also the bike will idle when cold but after running for a minute or two i have to give it gas. any suggestions would be appreciated. thanks
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I would check the float height. For the needle to fall out of it's seat ? The float tab my be bent.
That's why it is running rich and you have to give it a few rev's.
The correct height is hold the carb on it's side ( with pivot up ) and the float should be parrallel with the carb base with the needle just touching.
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What TMKIWI said.Also,does the tab just sit on the needle or is there a wire attached to the needle that goes over the tab?
As far as the bike idle for a minute or two then not,is that with the choke on?If so,that's normal-shut the choke off.
If that's after you shut the choke off,that's normal too and is how it's supposed to work.If that bothers you,like it does some on here :D,
turn up your idle screw a hair after it's fully warmed up.
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the needle has the wire that holds it on the float tab. i hardly ever have to turn the choke on and when i do once its cranked i can turn it of and its fine. I was told its not supposed to idle but didnt know if that had anything to do with the needle coming off. how do you change the float height and how do i know what height to put it at?
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You bend the tab on the float gently then flip the carb over to about 45' and measure from the top of the float to the flat of the carb body where the bowl sits.If you look close when you do this,you'll see the the tab touch the pin on the needle-if you continue to turn the carb upsidedown,you'll notice that the weight of the float depresses the springy pin on the needle.If you measure this way,you'll be wrong.
You have to measure at the point where the float tab just barely touches the pin-and doesn't depress it.
Measurements aside,a good rule of thumb is to have the have the float(usually there's a bit of a line or square edge before the float tapers in) level with flat of the carb body where the bowl sits-you'll see what I mean if you play with it.
Use a small screw driver to gently pry the float tab one way or the other to get this setting-it's usually better to take the float out and make your adjustment then put it back in and recheck.
Once you have it level,I usually set it so the float is just a bit "above level" This shuts your fuel off sooner so not so much fuel P's out your overflow tube when riding or when leaning the bike on the stand.
If you can almost start without choke(depending on your riding temperatures where you are)your carb is too rich.Blow out all the passages in the carb with cleaner and if it still does the same thing,we can give you more info for adjusting your airscrew properly or changing your pilot jet.