Author Topic: Adjusting idle screw, having to choose b/n hanging idle and bike dying when stop  (Read 74 times)

Offline BikerBoy

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So like the title says, Im adjusting my idle screw as I put in 135/60/20 jets and a K&N drop in air filter.. my bike either runs well, but will die when stopped without the choke on, or it stays running, but has a hanging idle...theres no sweet spot between them. The hanging idle goes away when I adjust the idle screw to under 1000 RPMs at idle, but then the bike dies when I stop it with no choke.

I havent adjusted the 2 air screws, 1 for each carb. I have the adjustable ones so I can play with them easily. Right now theyre at about 3 turns out. Would the solution be to screw the air screws in slightly, half a turn at a time, to fix my hanging idle? Or do I turn them out?? Thanks in advance  :thumb:

Offline The Buddha

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Try opening up the air screws a bit. 20 is good for pilots on a stock or drop in K&N and pipe, in fact 20 is ideal for all possible configs on a stock bore/stroke bike. You may need to go from 3 to 3.5 turn out on air mix screw - now if you're at 5+ I'd worry you are past its useable range, and may need 22.5.

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Buddha.
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Offline mr72

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Hanging idle is because idle is too high. If it won't idle when it is completely warmed up then something may be clogged. The k&n drop in filter is not going to make it easier. Stockish jetting and stock filter will make life easier. K&n filter doesn't improve performance and filters worse than paper.

Offline BikerBoy

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Hanging idle is because idle is too high. If it won't idle when it is completely warmed up then something may be clogged. The k&n drop in filter is not going to make it easier. Stockish jetting and stock filter will make life easier. K&n filter doesn't improve performance and filters worse than paper.
Would taking off the restrictor on the air filter help (adding more air, leaning it out)??

Offline mr72

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That won't add more air. It'll just slow down the air and require different jets.

Offline The Buddha

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So like the title says, Im adjusting my idle screw as I put in 135/60/20 jets and a K&N drop in air filter.. my bike either runs well, but will die when stopped without the choke on, or it stays running, but has a hanging idle...theres no sweet spot between them. The hanging idle goes away when I adjust the idle screw to under 1000 RPMs at idle, but then the bike dies when I stop it with no choke.

I havent adjusted the 2 air screws, 1 for each carb. I have the adjustable ones so I can play with them easily. Right now theyre at about 3 turns out. Would the solution be to screw the air screws in slightly, half a turn at a time, to fix my hanging idle? Or do I turn them out?? Thanks in advance  :thumb:

Go to 3.5 richening it slightly. You're almost there if this is your only problem.
BTW K&N in the airbox is dirty as hell and the paper one is reuseable by washing it with gas and drying anf putting it back in, I don't even know why bother with K&N drop in.
Cool.
Srinath.
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