Hi all

I have a 2003 Kawasaki KMX 125, one of the last made. It has been in a barn for the last 4 years with minimal use. It has only done 1,700 miles from new. Everything is fine generally, it starts and runs no problem. However it has a nasty stutter between 4000 and 5000 revs in all gears. If you twist the throttle full on it will go through this with only a minor blip but if you need to hold between these revs it splutters quite nastilly. It's smooth up to 4000 revs and once past 5000 revs it flies up to 9000 without missing a beat. Any help to get it running smoothly at this rev range would be much appreciated.

Jeffers, July 2009

Thanks very much for that. Makes a lot of sense. Am about to go on holiday but will try it when back and repost result. Thanks again.

Jeffers, July 2009

Hi,

I would put money on your carb needing a clean. Easy to do but if your not sure get someone who knows what they ae doing to help. Petrol would of sat in the carb for all those years and gone off as it were. One or all of your jets will be slightly blocked.
If you want a go at it here is how.
Before you take carb off turn petrol off and run bike until it runs out of fuel, Carb empty.
Take carb off it wil be attached to your air box and your cylinder head. Also petrol pipe and choke. You will have to unscrew top of carb as well. Take a piccy first to remember how it goes.
When it is off the there will be 3 to 4 screws at bottom of carb take these off. These are generally soft metal so makesure your screw driver fits or you will destroy them. Soak in WD40 first as it has been sitting around for a few years.
when off it will see the internals of carb.
The floats are held in with a pin. Take this off and you will have access to main jet. Take this out and clean with clean petrol. Clean all jets with petrol and blow out. then put all back together.
Carbs are delicate. remember which way it goes and be gentle just take your time.
While your at it I would change you plug and your air filter. Grease cables as well. Just a bit of oil on the levers where the cables show. Good Luck

BB, July 2009