Problem with idle

Ok guys back in the garage and so close to getting this bike back on the road finally and now ran into another hiccup. So its a 81 kz750h ltd with keihin carbs that I stripped down cleaned and put back together. When i got the bike it was idling at around 4000 to 4500 and no matter what would not go lower. Started digging into it petcock was shot and needed to be rebuild. The carbs were really nasty and gummed up from sitting a lot and cheap gas. On top of it someone looped carb 1 into 2 and 3 into 4 for overflows guessing there way of fixing overflowing problems from petcock and sticking floats. So everything fixed and back on factory air box and replaced the air box boots.  So i can get it to start up and idle pretty good at about 1000 to 1200. Give it some gas and revs up great but then hangs around 3000. Cant really seem to fix the problem got new carb boots coming for engine side they showed some wear but thought i could get away with it for a bit. Going to recheck the polite holes when i take the carbs back off  seems like its running really lean even turning them out 3 turns but was wondering if it could be something else im missing trying to get the bike out on the road. Also can i vacuum tune the bike or should i just wait?

As always thank you guys this community is so awesome 

60/40 test
Tape up half of the airbox.
Is the problem still there?

Remove the tape and crack the airbox open.
Is the problem still there?


Mike Nixon's 60/40 test
www.motorcycleproject.com/text/the_60-40_rule.html
 

Multi-post
Ugggh
 

Thanks I'll give that a try tonight and see what happens 

Ok did the test and still is doing it hangs right around 3000 to 3500 even with air filter completely out. Pilot holes pluged?

Lean mixture, most likely air leaks is the most common cause for an idle like that.  A bad sync can cause a high idle too.  Plugged pilot jets will cause the affected cylinders to not fire.

Ok guys finally got parts in and had some time to work on the bike and still has a very high idle i cant seem to figure it out. New boots on both sides, idle mixture ports are all clear and turned out 2 times. Bench synced again and original was off some. If i close off some air it gets even worse im really lost here also while I had the carbs off the bike rechecked the plugs in the bowls and they looked like they were in and good. 

Is there any free play in the throttle. Check cables. 

 

Yeah got about 1/16 to 1/8 

wrote:

Yeah got about 1/16 to 1/8 

Have you checked the timing advancer. 

No i haven't  not really sure how to and it starts fine and half the time it will idle right until you give it some gas then it just goes up and stays there

Timing advancer is under the breaker plate.