high revs

recently bought a kz1100 ltd l1 1983. the bike doesnt rev down when changing gear and when sitting still it just revs up on its own accord to 5000 rpm quite scarey does anyone have any ideas what it might be? I have checked the inlet rubbers and they seem ok :(I got a shop to fit new intake rubbers and clean the carbs and to set them up the bike is going much better and she doe'nt rev up now yippee

They may "seem" ok, but it is absolutely necessary that the system is not intrduced to outside air, even miniscule amounts will cause this symptom.

Remove the carbs, then the boots from the engine. Use a good (must say gasoline resistant!) gasket sealer like Permatex Motoseal - gray tube. You can use paper gasket from a local hardware store and cut your own, just greese each side of the gasket before installation.

Make sure everything is nice and clean before install.

Both sides - engine and airbox, must seal air tight to prevent the lean rev-up.

Try spraying some wd40 around the carb intakes, the carb tops, linkages, chokes, etc... anywhere that air could suck in, and watch for a change in exhaust color and an audible change in the engine/rpm.

Good luck.

Could also be a throttle cable problem. It (they) might need lube or it (they) might be frayed and need replacement. Might even possibly be glorp under the throttle tube (hand grip) causing poor return. Maybe all the above. Then there is the return spring.................

TexasKZ wrote: Could also be a throttle cable problem. It (they) might need lube or it (they) might be frayed and need replacement. Might even possibly be glorp under the throttle tube (hand grip) causing poor return. Maybe all the above. Then there is the return spring.................

Yes, thats what I was trying to remember :laugh:

Could be so many things that will hang up the throttle cable. Look at the carbs when revving the bike, to see if the throttle returns all the way to stop when the revs hang.

Hey there, I'm actually dealing with the same problem, and I'm finding that mine was due to tight valve clearances on the exhaust cam, only happens when the engine gets heat in it. I've been told to sync the carbs, the advancer might be stuck or broken, and many more things, refer to the thread "mikunis won't idle down" for more ideas. One thing I will mention, is when it revs at idle like that, if the engine starts getting hot and the fuel bowls of the carbs get real cold, you may have the same problem I do with valve clearances being too tight.

Ed

I had this on my 305. Different carbs of course but my problem disappeared after carb cleaning.

Many thanks tek9ine will get stuck in about her this week end. I have a set of carbs from a kz1000 ltd think I'll try them on as well just to see they work any better.

Many thanks Texaskz I have tried all the throttle cable checks and there are all ok wish it was just that tho

After replacing my boots I encountered a similar problem. Not quite as high of a rev. I didn't use any sealer though, gotta try that. When I spray carb cleaner on the boots it revs higher, and plugs are pretty ashy. So for me, I'm sucking air and running uber-lean.