won't idle down sometimes

Hope everybody had a great holiday.
Took my bike out for the first time in months yesterday and not all the time, but sometimes the thing wants to rev with the throttles closed. I checked to make sure it isn't the cable or linkage by feeling the cable wheel thingy while operating the throttle. The linkage closes all the butterflies (as best as I can tell), but sometimes she'll keep revving. But most times it operates normally. So unless I have a vacuum leak that only leaks sometimes, I don't know what this is.
Anybvody know off hand?
Anyway in the mean time, the temp here is supposed to climb into the low sixties and the sky is blue, so, I'M OUTTA HERE!:woohoo:

A hanging idle is a classic sign of an intake leak. Check your intake boots and your airbox boots (if you have an airbox). The reason it only happens sometimes could be relative to the temperature of the bike. Often times it happens more when the bike is warmed up good.

Well I just put brand new boots on last year. I suppose one might've loosened up a bit. I'll retorque thewm all.
But I rode all day yesterday and it only did it once less than a mile from my house. Rode 120 miles and it never happenmed again. May be that temp is an issue, but opposite in that the leak somehow closed up as the motor warmed up.

Anyway, met a guy in a bar with a brand new Harley clone. Think he said he has bg inch Ulima". He spied my bike and asked about it. He's never heard of a KZ1000.
In short, we went for a blast up the river road.
Now he knows what a KZ1000 is.:laugh: :laugh:

An 80 KZ1000 with throttle butterflies? Are these BS34s or are they the stock VM28?

riverroad wrote:

Took my bike out for the first time in months yesterday and not all the time, but sometimes the thing wants to rev with the throttles closed

Not sure if your problem is like what I had but, the cure for mine was the mechanical advancer. Check it to see if it's gunked up. I cleaned mine and re-lubed it and all is well now.

Good Luck,
Sonny

George, I was wrong when I referred to them as butterflies.
They're the stock VM28 slides.
Sbula, I just cleaned up my advancer last year. Maybe I oughta have another look at it. Thanks.
But as thew temp just dropped to twenty degrees this morning, I think I'll wait on that a while.

My guess would be air leak or throttle cable binding.

Mine did it with a binding throttle cable. When I got the return installed and set right it went away. Thats what I get for altering cables myself instead of taking the hit and ordering the custom ones.

You might try adjusting the slack so as to give the return a little more pull and that may allow the throttle to pull them closed. Just as an idea.

Thanks guys but it ain't the cables. I can reach under the tank and feel that the throttles are closed while it revs.
In any case, it's not doing it anymore.

Do you still have the smog control on it? I could not for the world of me figure out what was causing me the same problems last year. I had removed the smog control and put a chunk of cheap auto heater hose between the 2 ports. I was sitting at work having a cig one day, when I just happened to look at my bike. The hose was split all the way almost, but on the inside, so it was hard to see. I went to the local advanced auto, and the guy gave me a couple of large vacuum caps that he just happened to have left out of an open package. Problem fixed, bike ran like a charm after that.

Hi, when i got my kz i found the carbs were not kinked together in the middle. the carbs are paired left and right and the link in the center is mechanicaly connected in one direction and spring returned in the opposite. they didn't time the shafts right, and that allowed one pair of carbs throttles to move freely (a small amount) because the link was stuck in the spring. if you had carb work recently i would have that checked. joe