Dissapointed with my 03 CR250

[Not2Sure]

Bought myself an 03 CR250 and before i even took it out for some hot laps i ripped her to pieces and replaced and rebuilt anything and everything and she now looks like a bought one. So the weekend came along and the mates and i went riding. Me on my bike and friends on 02 yz250 , 05 ktm 250sx and 99 yz250 and yes i know in stock form the cr isnt up there with their bikes which are all stock also but none of them have to worry bout me gettin near them in a plain old drag race. Thing is i love the way it handles and it looks the part to. Its jetted near perfect as is and i know my s#@t when it comes to dirt bikes since ive had nearly 30 bikes and done all work myself and im a mechanic by trade. Now im broke and havent got bugger all cash to throw at it after all the work ive done to it already so im wondering whats the best performance mods i can do to wake it up. Ive seen a few forums on here about what ppl have done to get their cr singing and we all want to get everything on the market and bolt it on blah blah blah. Cant afford much now so im tossing up on getting v force reeds or fatty pipe or turbine core 2 etc etc. If there is one thing i need to get those extra horses i gotta know now already over them bagging the ever trusty honda.

[Huffa 2]

Who cares about what bike is faster in a drag, it's who has the most skill on the track or trail!

You do moto it, right ?

[Not2Sure]

Couldnt Care less whos bike is faster either my point is after totally rebuilding it and goin out for its first ride it doesnt really stand a chance against my mates bikes which are abused and flogged and havent had a rebuild in years. Ive had 5 other 250 2stroke mx bikes and the only 1 that wasnt any better was the 2000 kx i had. So for my own personal benefit i was wonderin whats the best bang for buck mod people have done to these crankcase reed induction engines. I rode a 2001 cr250 years ago and loved it and thats when i had a KTM 380 SX so i know its just a matter of spending money on it and i will be happy and any advise would be appreciated

[Cable Stretcher]

The bigest bang for your buck is to have the crank case epoxied and the V-force.

[Huffa 2]

You sure it is not just the smooth power delivery fooling you, making you just think it is a lot slower?

I thought that is what I read a # of times, that since the bike does not really have a major hit in the powerband it just feels slow but in reality it is more tractable getting a bit more power to the ground ?

[Not2Sure]

Dont get me wrong i like the power delivery which is why i mentioned my old kx 250 also smooth but a tad weak compared to a YZ or KTM 250SX from the same era. In a rolling race with other 250's in top gear from approx 40mph i was 4-8 yards behind them when i topped out all bikes stock including gearing and on bitumen or dirt/gravel. Ridin other ones over the years with mods and they were good. Every body says the same thing being that they are tame and really benefit from some work having no trouble making 50 useable HP.

[KcDavis]

Ever consider operator error over the bike's faults?

[moto_123]

Could also be a difference in rider weight / aerodynamics at that speed. Or as simple as different tires or tire sizes.

The easiest thing you can try is running race fuel and make sure your chain is good and loose. Maybe switch to a non-oring chain if you have one lying around.

[DoctorRzed]

Mess with your gearing, its cheap to do.

I'd tear it up on a stock CR250, just give me some suspension and its an amazing bike even in stock form.

[Big_G_Hall]

Mess with your gearing, its cheap to do.

+1. What ratio are you running right now?

[rolandk]

There is something very wrong with your bike and/or riding.

[SubTexel]

There is something very wrong with your bike and/or riding.

Yeah, something isn't right.

You should be walking all over those other bikes unless your bike is clapped out, you aren't shifting right, have a bald tire, or weigh 250+ and they all weigh 170-185... Or all of the above.

[bikesnwheelers]

I have a set of V Force 3 Reed/Cage. PM me if interested.

[Old-Timer]

In a rolling race with other 250's in top gear from approx 40mph i was 4-8 yards behind them when i topped

OMG dude......no wonder you lost.

Drop a couple/few gears and twist it open.

40MPH in top gear?

It's a dog at low RPMs.

When the green flag drops, down shift and pin it.

Hold it open 'till the power starts to fade and click the next gear....don't even bother to let off.

That's how they're meant to be run.

That's how I rode mine.

As for cheap power mods?

Clay-check the piston-to-dome clearance and mill the head....not talking a measley .030 (could probably shave .090/.100 inches).

Raising compression is the single most effective mod you could do, but you'd have to rejet accordingly.

I Play-Doh'd my piston. Took around 1/8" from mine (I'm not joking).

My CR250 went from so-so, to ballistic with that one mod.

Tweek the timing.

Port the piston.

Drop a tooth on the front sprocket.

Lighten the flywheel.

Bel Ray at 50:1.

Been there, done it........

[703]

have you checked lubed and ajusted the cables on your power valve?

check that the servo motor is running free the have been known to corrode up and not work right or at all my 05 had a seized servo and needed a new one that bike should always put a smile on your face

[mtgraves]

Check the power valve servo for proper settings and operation, and slap in the V-force 3 setup. That was the single best mod I did to mine. Probably the only thing besides messing with gearing that I could tell all that much difference. You're gonna have to re-jet it, but it's well worth it.

[Not2Sure]

Just so happens i ordered a v-force 3 setup today. Went to the local honda dealer after work and had a good chat to the head mechanic and he said you cant go without them on the 02 on 250. Also forgot to ask him the correct adjustment for the powervalve cables too although im pretty confident they are adjusted right?

[FrankV]

Just so happens i ordered a v-force 3 setup today. Went to the local honda dealer after work and had a good chat to the head mechanic and he said you cant go without them on the 02 on 250. Also forgot to ask him the correct adjustment for the powervalve cables too although im pretty confident they are adjusted right?

Here's MXA's howto.

[yz133rider]

Get it ported for mid to top end power and get the head cut for 50/50 race gas and pump gas. She'll stretch your arms out after that.

[Cjacob74]

New carb.