Make sure your not sucking carb cleaner in the carb giving you a false leaking seal reading. Use a piece of cardboard as a baffle or wall to prevent the carb from sucking in the carb cleaner. YD

 

Maybe I'm jumping the gun because I haven't checked the timing or changed anything on the ignition, but the mixture screw still does nothing on my ride. I've got the idle running smoothly 900-1000rpm. The bike starts immediately and runs pretty well I think. The spark plugs are nearly identical in color, with the rear just slightly richer (not like before when it was black and white difference).


The only thing I have not confirmed or resolved is a possible manifold leak. Last I tested, I thought both front and rear were bogging down with carb cleaner, but I could have been overspraying it. Will test again.

 

ok lurking here,,,last post 6/7...today is 6/12 ...well??? hahha its like a mystery novel..what happened???

 

If you had a manifold leak, adjust the idle mixture screw in all the way would kill the motor... However the fact that any adjustments to the idle mixture screw still makes no difference says that there is still something wrong. Your sucking fuel from somewhere....

 

So one source said that the pilot jet might be too big. I'm running a 45; I could source a 42 and 44 to see what happens. I could replace the float valve. I think my choke is functioning properly. Those are the only three things I can think of that affect fuel flow at idle. Anything else?

 

I'd go back to the 42 pilot. Earlier you stated that when turning the Idle mixture screw in all the way (lightly seated) you could see it sticking through the hole... I'm not 100% sure that it should protrude into the venturi.... It is known that if the needle is screwed in to far (closed) it could do damage to the carb and I would imagine that it would totally affect the idle circuit where the port in the carb body would be to big and would allow for more fuel than normal.... Also I'm wondering if there is a main jet air bleed and if that is the correct size? just trying to help...

 

I've ordered a 42 pilot and a new float valve, so we'll see what that does. I haven't ordered a replacement mixture screw because I can't see anything wrong with mine. I would be surprised that the screw entering the venturi would cause a permanent problem. I understand your theory on the needle boring out the port if someone cranked down on the mixture screw.


What do you mean by a main jet "air bleed"? Maybe I've overlooked this.

 

Sorry that's on the older Keihin Cv carb...