RS38 issues

[CB900SS]

Well I took my bike out for a short ride and all seemed good with the mikuni carbs. But today it didn't go as well.

I went a few miles and stopped at a light and the idle was at 2,000 or so. At the next stop a mile or so away it climbed to 2,500. I turned the idle screw down to 1,100 and it was good for a mile or so and then it would stall, I kept it running with the throttle. I didn't adjust the screw and all of a sudden it was idling fine again... Then it climbed again and I adjusted it even further down.

So I sprayed the intake boots down and the carb top down that has a temporary cardboard gasket I cut. The bike never revved up so I don't believe I have any air leaks.

My new fuel filter was not full at all so I think I'm going to eliminate that. I am going out in a few minutes to pull the plugs.

Also, I have some slight popping through the air filters once and a while. But very, very seldom.

Thanks!

[CB900SS]

In order, 1,2,3,4

Its got to be my homemade gasket on #4 carb top?? But I was thinking that would suck air and make it lean??

[Billy Ricks]

If the gasket is shaped right it shouldn't be a problem, not the problem you have anyway. You're rich on 4 and that could be a couple of things. Float level on that carb could be too high and maybe fuel getting past the o-ring on the float seat. Could just need the idle mixture screw turned in.

[CB900SS]

Alright, my racing and funky idle is fixed. The problem was un-related to #4 being rich.

The spring on the idle screw that stops it from turning wasn't putting enough pressure on the screw and the vibrations caused the idle screw to move. I stretched the spring and all is good... I should probably get a new spring in there.

I would still like to check my float heights. How do I do this?