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Old 03-22-2009, 03:24 AM
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dacaur
 
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Default RE: Alittle help with engine tuning plz.


ORIGINAL: svroddy

So full throttle is controlled by the high speed needle only?
Yes. All the low speed needle is for is so you can lean your idle so it doesn't load up and flood as fast at idle, but you still get enough fuel at full throttle... All of the fuel comes in through the high speed needle, and the low speed needle simply restricts it further, but only until about 1/4 throttle, once you pass that, the low speed needle has absolutely no effect. If you have a slide carb, you can see this. With the engine NOT running, take off your air filter and look inside the carb. Now slowly open the throttle and look down inside the hole the opens up, you will see a little bar inside the goes into a hole when the throttle is about 1/4 open, that's the low speed needle. once that comes out the hole, its no longer affecting engine operation at all... That's why you tune the high speed needle first, because the low speed needle just further restricts the fuel that's let in by the high speed needle.