late model cr250's

[longtime coming]

I'm shopping around a little to find a late model CR250 (case reed engine, new frame) for a motocross bike. I just like Honda's. Sorry. Anyway, there is much to-do about hard jetting, no bottom power, explosive hit into midrange, detonation, etc on these engines. I know of one case of two identical 06 models that just don't run nearly the same and one has been a bit of a nightmare (clutch problems, among other things) and the other has been solid.

Are there quality control issues, or known problems with any '02-'07 models? How hard is it to smooth out the power? Will it ever be smooth and linear like the '08 200xc we have which we set-up to be this way (stock but tuned).

thanks for your replies

 

[dirt bike dave]

FWIW, I remember there was an old thread ages ago where someone wanted to turn an '02 into an offroad bike. If I recall correctly, they were unhappy with the lack of low end, but loved the bike otherwise.

The end result was porting the motor for low end made the owner very satisfied.

 

[_JOE_]

Right, as long as you plan to alter the porting you can make it whatever you want. Turning any close ratio tranny MX bike into a smooth woodser will require some work. Porting, power valve adjustment, pipe and gearing should get you close, engine wise.

It seems the rider has the biggest impact on reliability. Maintenance and riding style can cause big variences in service life.

 

[longtime coming]

Thanks for the replies. Once I find the bike, I'll figure out what to do. I'm hoping a couple of cheap bolt-ons will be enough (reeds, flywheel weight, gearing). Who knows? I haven't found an engine builder within a thousand miles of here (yet). I'll be working on it. I might even end up with a Yamaha if one comes along :p.

 

[ulmanb]

I have a 05 that I use off road only (no mx). In stock form I hated the power. crappy transition from low end to top end, hard to jet and finicky.

The JD jet kits work well, but they still are finicky to temp changes with the JD kit.

I had been running it with a 38mm keihin from a 2000 cr250, that ran very well and more easily jetted. I then installed a 36mm keihin from a 2006 ktm300. This is the carb that honda should have installed. Easy to jet, pretty smooth transition from bottom to top.

I also added the typical woods stuff: 10ounce flywheel weight, re-geared sprockets, oversized tank, boyesen power reeds and spark arrestor.

I initially bought the bike cheap to resell for extra cash, but I like it too much now. Ranks up there on the fun factor scale with my ktm 200.

And I love the handling of the cr.

 

[longtime coming]

Thanks for that. I guess that smaller Keihin carb is the key then. Something in me just thinks that the cr250 is an exeptional bike IDKW. We bought an '06 Cr125 when some research indicated that it was a turd. No way! It is a really, really good bike. I'm guessing the 250 is just misunderstood also. As long as it has no inherent mechanical gremlins???? :)

Does that carburetor somehow solve the detonation issue??

And that's what I'm after, is the CR handling. The 125 is really nice. I'm thinking the 250 is similar, in a girthy steroidal sort of way?