98' 400 slide?

[jetfuel]

I'm working on a 98' 400 thats been idling erratic, it begins idling slow then if the throttle is blipped the idle hangs high for 5-10 seconds then drops back down and occasionally stalls.

One of the strange things I found was that the idle screw has been screwed in as far as it can go yet doesn't idle high when first started ?

I did some searches and found the problems with slides cracking, I pulled the slide and found an extremely small crack starting on the Rt. lower corner in the radius.

Is it possible for this minute crack to cause this type of idling problem?

It seems the owner kept dailing in more and more idle adjustment as the problem progressed, is this also related to the cracking symptoms?

Thanks, Jetfuel

[PoorComa]

I was having similar problems with my 2000 400. I replaced the piece that attaches to the float (needle set?) and my problems have been cured. Got it to pass emissions and all!

[Frostbite]

I'm working on a 98' 400 thats been idling erratic, it begins idling slow then if the throttle is blipped the idle hangs high for 5-10 seconds then drops back down and occasionally stalls.

One of the strange things I found was that the idle screw has been screwed in as far as it can go yet doesn't idle high when first started ?

I did some searches and found the problems with slides cracking, I pulled the slide and found an extremely small crack starting on the Rt. lower corner in the radius.

Is it possible for this minute crack to cause this type of idling problem?

It seems the owner kept dailing in more and more idle adjustment as the problem progressed, is this also related to the cracking symptoms?

Thanks, Jetfuel

I just fixed a hanging idle on my 99 400. My problem was caused by air leaks, but I also had a slide plate break a few years ago.

A small air leak doesn't affect the engine much at higher RPM, so maybe that's why the idle screw is cranked in. If it is a cracked hose like mine, it probably started small and grew, so gradually turning up the idle to keep the bike rideable would make sense.

The cracked throttle slide plate actually lets more fuel/air mixture in the engine (not just air) and has the same effect as turning up the idle. When my first cracked I had to turn my idle screw out to keep the bike rideable, since it was revving too high.

Frosty

[jetfuel]

I just fixed a hanging idle on my 99 400. My problem was caused by air leaks, but I also had a slide plate break a few years ago.

A small air leak doesn't affect the engine much at higher RPM, so maybe that's why the idle screw is cranked in. If it is a cracked hose like mine, it probably started small and grew, so gradually turning up the idle to keep the bike rideable would make sense.

The cracked throttle slide plate actually lets more fuel/air mixture in the engine (not just air) and has the same effect as turning up the idle. When my first cracked I had to turn my idle screw out to keep the bike rideable, since it was revving too high.

Frosty

AH HA!

That was just the info I was looking for ...

Thank you very much Frostbite. ?