XJ650 Starts and runs great but does not want to idle.

XJ650 Starts and runs great but does not want to idle. It runs fine with choke on, but when choke is off and just left alone the idle just gets slower and slower until it finally dies. I cleaned the carbs out and found a clogged jet. I fixed that and the bike just does the same thing. I was wondering if anybody has any ideas. My ideas; they could and probably are way off but the petcock could need to be rebuilt, the yics passage needs to be cleaned out(I dont know exactly what this passage is if anyone can enlighten me), general tune up. But I dont know so any help would be appreciated thanks.
Andrew

 

Forget the YICS passage. Before '82 the bikes didn't even have them. We plug them up for tuning. Supposedly they improve idling and emissions.

Most likely you have an air leak, dirty carbs pilot mixture screws not set correctly.

Pilot mixture screws are on the top of the carburetors, at the front, next to the enrichment plungers. They come from the factory with a little brass cap in the hole. If yours has them you need to dig them out carefully so you don't damage the mixture screw underneath. Most people find the best setting just shy of 3 turns out from seated.

To check for leaks you can use an unlit propane torch. Let a little propane around the carburetor supports and butterfly shafts in the carburetors. A change in engine speed indicates a leak.

Most of us have to clean our carburetors several times before getting then done right.

Finally, these bikes don't really idle well cold. You will probably need to run it on "choke" for 5 minutes or so before it will idle without enrichment.

 

Just found the problem i feel really stupid but maybe someone can learn from it. When I cleaned out the carbs and put them back i didnt tighten the choke cable and as soon as i fixed that she runs great. Thanks for the help.