Carb tuning question, picture included

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Florida_Rider · Sun Mar 19, 2006 6:56 pm

Heres a pic of my carb. I know the bigger screw (right) is the idle, but what is the smaller left one? I've been playing with it and it changes to many things that I can't guess what its doing. Hopefully it will help the problem that When I shift into 2nd i lose a ton of low end power. I have to wait for the rpms to climb until I get going again.

BuzZz · #2 Unread post by **BuzZz** » Sun Mar 19, 2006 7:45 pm

That's the idle air screw. It affects the fuel/air mixture at idle and up to about 1/4 open throttle settings. Don't screw it in tight, it is a tapered screw that controls flow through an orfice and if you deform the end by over tightening, you'll bugger it. It should be set someplace between a full turn out from bottomed to 3 turns out at most.

Florida_Rider · Sun Mar 19, 2006 9:16 pm

wait if the one on the left is the idle, then im really confused. I'll set it as you said and get back tomorrow, thanks

#4 Unread post by **Skier** » Sun Mar 19, 2006 9:29 pm

Florida_Rider wrote:wait if the one on the left is the idle, then im really confused. I'll set it as you said and get back tomorrow, thanks

I believe he meant the one on the left is the idle air mixture screw, the one on the right is the idle speed screw.

BuzZz · #5 Unread post by **BuzZz** » Sun Mar 19, 2006 9:53 pm

Yes, that's what I meant. The one on the right affects the slide hieght to change idle speed, the one on the left affects the jetting at lower throttle settings.

Florida_Rider · Mon Mar 20, 2006 2:56 pm

I set it at 2 turns out from bottom and it seems to work pretty well. So if I understand, the more I loosen it, the higher the idle up to 1/4 throttle? That would seem like where I need it the most. I'm goning to 2.5 turns out and see if second is a bit smoother.

BuzZz · #7 Unread post by **BuzZz** » Mon Mar 20, 2006 7:21 pm

The fact it changes the idle is only due to the fact that it changes the fuel/air mixture at those throttle openings. It is not the primary adjustment for the idle, the other screw(one the right in your pic) is for that. You set the idle/air screw to where the bike runs best at low throttle positions, then set the idle speed with the other screw.