high idle/weird revs

[ITSSLOW]

Rebuilt the carbs on my Kat a few weeks ago. All seemed alright at first but now its idling super high (4,000rpms) and turning the idle adjustment doesn't change it whatsoever. When I choke it the engine jumps up another 1,000rpms so thats working. When I would rev it up slowly it would return to idle as normal. When I would rev it up quicker it would rev up normally but rev down slower. Then I cracked the throttle and it just stayed at 4000. The throttle seems to move just fine so I don't think its a cable. Stuck slide? vacuum leak?

[akarob]

Either a vacuum leak or it's starving for fuel. I always suggest using a .020 wire on the emulsion tubes to clean the small holes out. Its seems that it is the only way to get them clean. Mine ran just as you describe until I got those holes reamed out.

Are all your cylinders working at idle? Check to see if all the exhaust pipes are hot.

[nicholaskumm]

I had the holes cleaned out, carbs professionally cleaned. Ran perfect for one day. Now the next day I am having same problem as you ITSSLOW

And Also have no vacuum leak. So I have no idea dude

[1990gsx 600]

rust in your tank is clogging your pilot jets and gumming up the main jets.... thats my guess..... i wouldnt use wire on jets or emulsion tubes cuz you risk widening the holes.....also a symptom of an air leak is a bouncy idle not high idle so you may have a stuck chock plunger or as i said before you prolly have stuff int eh tank clogging jets

[ITSSLOW]

The tank isn't rusty. The gas that was drained out of the tank after sitting a year wasn't brown or anything. Just smelled stale.... I'd imagine its firing on all cyl but I'll have to check tomorrow morning. Too late to fire it up now. One neighbor would be out tinkering with me but the other would be calling the cops! lol

[1990gsx 600]

well than i would say you have a lean idle circuit ..... im sure someone else will chime in here soon and say for sure

[ITSSLOW]

Finally got around to tinkering with it yesterday. It fired up and was idleing like normal until I reved it up and the revs went up and stated up. I reached down and all 4 of the black, plastic, slides were all the way down. I took my fingers and moved two of them up and the idle came right down. When I let go of them and they dropped back down and the revs went right back up. Aren't those for the choke and vacuum operated? To me, that says vacuum leak. I'd think they'd need some kind of vacuum on them at all times to lift them up. No/light vacuum and they won't stay up and its like choking the engine at all times.

[akarob]

Your vacuum leak may be the fact that your airbox isn't on. I only know a PRE 98, but you must have the airbox off to touch the slides. You need to have everything in place to tune it.

[scottynoface]

Vacuum leak...

[ITSSLOW]

Your vacuum leak may be the fact that your airbox isn't on. I only know a PRE 98, but you must have the airbox off to touch the slides. You need to have everything in place to tune it.

It also does it with the airbox on as well. I took the airbox off to see if the slides were opening when I started the bike.

[1990gsx 600]

Your vacuum leak may be the fact that your airbox isn't on. I only know a PRE 98, but you must have the airbox off to touch the slides. You need to have everything in place to tune it.

at idle it dosent matter if the air box is on there is so little air moving......