last week i took off the air box and the air filter and cleaned it both. i have a uni air filter w/ outerwear and the filter was like perfect so i dint touch it. although i did take off the outerwear and cleaned it and sprayed it w/ filter oil. i also got some 110 race fuel and mixed it about 50/50 w/ 92 pump gas. now when it runs it idels pretty fast. i screwed the black screw towards the top of the carb in and out and it did nothing so i put it back where it was. what would cause it to be running so fast? i think its running lean. maybe i have a air leak some where around the filter??? any other ideas?? Thanx

 

your sure your adjusting the right screw. the one with the spring behind the head.

 

yes, its the black screw towards the top of the carb w/ a spring behind it.

 

I didn't know that you're supposed to spray the outerwear with filter oil. Seems as though it would restrick air flow an/or clog up. Am I missing something???

 

i dunno if your supposed to or not...but i sprayed a lil on it

 

If you removed the intake or manifold boots while removing the air box you may not have put them on completely, all the way around allowing a big air flow to enter your carb. This would account for the high rpm at idle. Also a loose hose clamp.

 

i got it fixed...it wasnt a air leak but it was the slide not going shut all the way. thanx for your guys' help!!

 

glad you found your problem, the black plastic screw w/spring behind it is the idle speed screw. It doesn't change the speed very much, maybe 100rpms. But there is a idle mixture screw that is brass and is located on the intake side of the carb that will change idle speed much more. It should be 1 to 2 turns out, but you did the correct thing and found the problem and didn't change your setting. To many people don't research why things have changed and start turning screws and changing jetting and end up chasing there tails in the end.

 

Doesn't the air screw affect the amount of air bypassing the closed slide of the carburator? If so, wouldn't the air intake leak prior to the carb be irrelevent?

I am not being a smart ***, I want to know because I am fighting the opposite of this guy.
My R will not idle no matter what I do. You seam to know what your talk about on your furom replys. I put a post up under "Honda ATV" section and was hopeing you would find it and respond. If you have time i would appreciate it.

I have completely disassembled the carb, clean, inspected all components and blew air through each passage to ensure it would pass fuel.

I have adjusted the air screw from 1/2 turn to 3 turns out with a slow jet of a 40, 42 & a 48 with NO AFFECT.

The quad will start fine if you just give it a slight bit of throttle (which lead me to believe it was starving for fuel). Becuase of this I turned the air screw in slowly to 1/2 turn while the thumb throttle is barely on to keep it running and this didn't help.
So I put a 48 slow jet in (a 42 was in it), same.
Tries to go the other way (40), same.

All of this with the idle screw from all the way in to all the way out, no affect. The idle screw is actually moving and removing the idle screw/choke **** appears fine.

Any help you can give would be appreciated.

Thanks, Nick Adams

 

try adjusting the idle mixture screw(brass screw) on the carb, it contols the amount of fuel to the motor at idle. The idle speed screw(black screw w/spring) adjusts a small amount of air to the motor at idle and makes very little difference.

idle mixture screw- turn in to richen,out to lean.

you could check Keihn's web site