GZ250 Idle/reving problem.

[Westfield]

Hi,
My GZ250 is over reving at idle. It will rev at a high rpm when it should be at idle but is not stable at that higher rpm. It will eventualy gradually and slowly creep down to idle sometimes, then a small twist of the grip will send it back up again. The cables and grip seem ok and it sits on the idle stop screw while its over reving. Adjusting the throttle stop screw has little effect.

It seems to be getting worse in that it used to creep down to idle more frequently. When being ridden at normal raod speeds it will jerk it's way along the road while accelerating.

Any ideas anyone ??

[awayatc]

Well.... a few ideas allright....
It sounds like you either have a problem with the slide in your carb or needle not descending as they should, or you are getting to much air...either your air mixture screw to lean, an airleak or some dirt in the carb somewhere...(a tiny speck of dirt in the wrong spot ..)
either way, you be better off to take carb off and have a good inspection/ clean....
While your at it, it might pay to clean your fueltap/filter as well.....
Good luck:yes:

[Bren]

I have just had the same problem on my gpx...followed some advice off the kawasaki forums and fixed the problem (here) (http://www.kawasakimotorcycle.org/forum/kawasaki-streetbikes-sportbikes/62400-rising-idle-ex250-when-warm.html). Anyway I used Nulon Injector cleaner.
Result-Bike idles properly at 1500rpm. :banana:
Cost-$12.00 from Supercheap Auto. :Punk:

[Westfield]

Thanks for that. I bought some carb cleaner today and will start unscewing things tomorrow. However, I disovered that the choke was out a little way which accounted for thing apearing to get worse.
The problem as it stands now is that it is very slow to return to idle when revved and the bike will jerk under acceleration at road speeds (Does that mean it's too rich or too lean? I thought that it may be a carb/mixture issue so thanks for the confirmation. I'll pull the fuel tap and filter while i'm in there.

[breakaway]

Bike jerks? You mean it misfires? What does your spark plug look like?

<img src='http://www.aa1car.com/library/reading_spark_plugs.jpg'/>