Anyone out there with an 06 or 07 KX250?

[|garth|]

If you've got one or ridden one of these, was it seriously lacking in low end power? I've owned a 2007 for quite a while now and it's always had no power at low revs. Mid range and top end is really good once it gets on the pipe, but for a modern(ish) 250 I expected a much more even spread over the rev range. I've spent a bit of time on an 08 RM250 and it's way way stronger at low revs compared to the KX.

Would be good to hear from other people if this is normal for the KX or if it's just my bike and there's something up with it. At this stage it's basically 100% standard, no aftermarket pipe or anything. It's got 115 hours on it from new, apparently had a new piston at 100 hours, but I never saw any receipts so who knows.

[roadkillnz]

If you've got one or ridden one of these, was it seriously lacking in low end power? I've owned a 2007 for quite a while now and it's always had no power at low revs. Mid range and top end is really good once it gets on the pipe, but for a modern(ish) 250 I expected a much more even spread over the rev range. I've spent a bit of time on an 08 RM250 and it's way way stronger at low revs compared to the KX.

Would be good to hear from other people if this is normal for the KX or if it's just my bike and there's something up with it. At this stage it's basically 100% standard, no aftermarket pipe or anything. It's got 115 hours on it from new, apparently had a new piston at 100 hours, but I never saw any receipts so who knows.

I've got an 03, which has bugger all differences compared to the newer models. I find it to have plenty of go in the lower rpms. Has the RM250 got shorter gearing perhaps? I put a larger back sprocket on when I first got it, which changed the bike heaps, as it would stay on the pipe up hills in 3rd (at a speed I felt comfortable at). Back to factory now, since I'm more comfortable to keep it on the pipe in 3rd when going up rough hills etc.

Check out 1:25 onwards on my vid clip. Barely on the pipe, but you'll hear it climb revs and get on song without any trouble.
http://www.youtube.com/watch?v=PFKcmhX5fIE

Compared to my RMX, it has more power, and far snappier everywhere in the rev range, but that's probably mostly due to the heavier flywheel and detained engine on the RMX.

[del-solider]

My mate has one and have ridden it a few times and have always found it to have quite a strong bottom end the first time i rode it i was really surprised.
His is bone stock standard.

Compared to a yz250 Ive ridden its got heaps more down low but the yz is another beast up top!!

[|garth|]

Hey cheers for the reply, your bike definitely sounds like it's got a lot more power than mine at low revs. Yours seems to pull smoothly right through the rev range where's mine has nothing on the bottom then kicks hard when it gets on the pipe in the mid range. 2003 looks exactly the same as the 07, but didn't they make some changes to the cylinder/porting on the later models?

RM if anything has longer gearing than my bike, it's still in second where I'm well into 3rd at the same point on a track. Difference is the RM is happy at any revs where's I have to keep mine screaming all the time. Pretty sure there must be an issue with my bike, it shouldn't be that much different to yours surely.

[|garth|]

My mate has one and have ridden it a few times and have always found it to have quite a strong bottom end the first time i rode it i was really surprised.
His is bone stock standard.

Compared to a yz250 Ive ridden its got heaps more down low but the yz is another beast up top!!

Really? definitely got something wrong with mine then, no one would say mine has a strong bottom end haha.

On to the next question then, any experts on here have any idea where I should start looking for the problem? carb/power valve/new rings/something else? Pretty amateur at repairing bikes...

[scott411]

The 03 kx250 has similar body work to the 05 and later ones but that is about it the motor is totally different

Thenew moto that came out in 05 never had the same roll on power as the rms of the same power but a massive midrange hit a flywheel weight does them very well Kawasaki sell a heavy flywheel for them as well

[|garth|]

Yeah massive mid range hit pretty much describes the power of mine, it's almost like an on/off switch when it hits the mid and all of a sudden the bike takes off.

Sounds like Kawasaki made the motor worse for the later ones then, the roll on power on the RM makes them much easier to ride. Might have to look into a flywheel weight if that's the normal power delivery. Cheers guys.

[CHOPPA]

Yeah massive mid range hit pretty much describes the power of mine, it's almost like an on/off switch when it hits the mid and all of a sudden the bike takes off.

Sounds like Kawasaki made the motor worse for the later ones then, the roll on power on the RM makes them much easier to ride. Might have to look into a flywheel weight if that's the normal power delivery. Cheers guys.


Its a 2 stroke you gotta keep it revvin :) Clutch is your friend :sunny:

[Crabby]

edit - whoops thought you saif kxf.. doh

[cheese]

Flywheel weight transformed my bike, I liked the zing in it though. It didn't really take the snap out it just balanced the power.

Do you think that running the biggest size rear tyre would help absorb some of the power in a 2 stroke and add to fly wheel weight effect?

[roadkillnz]

The 03 kx250 has similar body work to the 05 and later ones but that is about it the motor is totally different

Thenew moto that came out in 05 never had the same roll on power as the rms of the same power but a massive midrange hit a flywheel weight does them very well Kawasaki sell a heavy flywheel for them as well

I stand corrected. It's good to learn something new everyday. I'd heard from a bike store that the newer versions only had subtle differences, not amounting to much overall, perhaps their knowledge only went as far as the 04 model.

[Pornstar]

It dont sound right mate, definatly check the power valve, could be stuck open.