proper idle speed?

'78 puch maxi

when i turn the idle adjusting screw two turns out, it idles very high. it takes four turns to make it idle at a low speed.

is this normal?

how many turns out is your adjusting screw?

please help me out, i know i should have it idle at the low speed, but this doesnt seem right how high it is idleing.

thank you

-mike

Re: proper idle speed?

It's nice to have a low speed, smooth idle.. it's quiet and saves fuel

There are usually two idle adjustments.. one is the speed screw and one is an air:fuel mixture screw. Idle requires a rich mixture.. lots of fuel and not much air. When you get it perfect, idle speed will be low but the engine will never die on you..

Get the bike good and hot and then adjust the speed screw to get the lowest idle speed possible. Then play with the air screw until idle speed rises a little. Lower the speed again with the speed screw... then play with the air screw again and listen for the engine to speed up a little.. Lower it again with the speed screw.

take it for a ride and see if it dies when you come to a stop or if idle is too high for comfort.. if it is, repeat the adjustment. It's important to adjust idle speed / air:fuel mixture on a hot engine.. If you do it on a cold engine, it'll only idle good when the engine is cold.

Re: proper idle speed?

Jason Luther /

the whole 1 1/2 turns out thing is just a starting point. every engine is different. listen to joe about the whole warm engine thing. my puch when i first start it up it races like a jet engine, but once it gets warm, the idle slows down. theonly other adjustment on the carb is the cable tension (coming out of the top of the carb), but if you can slow the idle by turning the idle screw out, then the cable adjustment is probably okay. its when you cant slow the idle down at all, even with the idle screw all of the way out, that the throttle cable is too tight and holding the carb open.-jason

Re: proper idle speed?

you saying that carb has no idle air-screw?

If so, yeah.. nothing much to do except get it hot and adjust speed.

Re: proper idle speed?

Jason Luther /

its just a screw with a cone on the tip so when you screw it in it raises the slide a bit. japanese carbs must be really different, more sensical i presume.

Re: proper idle speed?

Mike Turner /

thanks a lot joe, you really helped me out. i just got home at midnight and im not entirely sure that there are the two different screws. i think i only have one. even so, now i know more about what im doing, thanks a bunch

ill let you know how it goes.

-mike

Re: proper idle speed?

good luck with it.. If there's only the one speed adjustment (and air-fuel mix is regulated by fixed internal jets) I recommend that you take special pains to make sure there are no fuel or air leaks or vacuum leaks and that existing adjustments are set up properly, such as float level and choke or throttle cables, and that air cleaner is clean, etc...

Chances are that if the bike is tight and in good tune it will idle just fine..

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