Jump to content
Sign in to follow this  

best upgrades for 250f?

Recommended Posts

im about to buy a 05 250f and ive already organised to to get stiffer valve springs and new seats and race valves and while its there its going to get flowed,is there anything else i can do im looking to hoppfully make approx 5-6 more hp and more bottom and mid,pipes dont really look like they do much from dyno charts,what about a cam or vortex ignition any help would be Awsome

Thanks

Share this post


Link to post
Share on other sites

Ditto on the cam. theres a lot of hidden power in a cam. But you gotta be specific wether you want high or low power. Might be able to get 4 or more horsies out of it. Theres a lot of aftermarket cam companies out there like crower (heard good things about them), webb cams, and hot cams

Share this post


Link to post
Share on other sites

Talk with RHC from here as he has a good handle, mention if you want reliability or not.

Crower is very good at the billet cams. Regrinds are out there but do research.

Forward Motion is working up a hot package that should be out real soon for the CRF250. I am sort of a guinea pig for them and will give a full report after the first week in March when give it in a good run in florida and georgia.

Be aware that some tuners have a different perception of reliabilty. :cry: Some think 8-12 hours is normal for the power they get and then a total refresh. :cry:

Personally I would like to hear from more guys that run the 270 kit, hard. The CRF seems to respond well to the overbore. I worry about crank life under heavy race use. I am sure the Cam guys will have a hot setup for the 270 also in the future. The 05 head I think flows pretty well and some porting jobs only add polish and not ponies. A hi-Comp piston is a real good choice and adds a punch. The Vortex with the proper mapping (maybe a custom one) with good fuel can make you smile.

Share this post


Link to post
Share on other sites

4-5 hP is gonna involve some porting. Unless your talking big bore kit. A good exhaust and some race gas would be my first 2 choices, that will get you maybe 3 or 4 Hp , I don't know about 5.

Share this post


Link to post
Share on other sites

we cant race with that fuel here,but the pipe sounds like an idea any suggestions??and the porting sounds good

Share this post


Link to post
Share on other sites

yeh i ported my '05 yzf250 and i rekon it gave it alot more bottom end to mid. also there is a little bit of tweaking u can do to the airbox for better air flow that i found works good. a good idea also is a wiseco high compression piston

Share this post


Link to post
Share on other sites
yeh i ported my '05 yzf250 and i rekon it gave it alot more bottom end to mid. also there is a little bit of tweaking u can do to the airbox for better air flow that i found works good. a good idea also is a wiseco high compression piston

I agree. The high compression piston made the biggest HP difference on my bike. I went with a Dr. D exhaust primarily because I got a great deal on it and it definitely added some noticable punch, especially in the low end which is what I was hoping for.

There are better exhaust choices if you're looking for power. Do a search in this forum on "exhaust" and you'll find some good information.

The new piston, coupled with the exhaust, has definitely provided the punch I was looking for. I'm too cheap to go wiht a big bore kit right now and honestly, at my riding ability, I'm pretty sure any more horsepower would most likely get me into trouble.

Share this post


Link to post
Share on other sites

Try a Hot Cam and an aftermarket ignition.You won`t beleive the extra power and higher revs.I`ve seen both on ebay recently.I have a Procom ignition box ($130.00) and a Hot Cam ($170.00) and it really brought mine to life `05 CRF250

Share this post


Link to post
Share on other sites

SKILL and SUSPENSION.

Once you've got these 2 things dialed in, then go for the other stuff.

Share this post


Link to post
Share on other sites
SKILL and SUSPENSION.

Once you've got these 2 things dialed in, then go for the other stuff.

agree'd i know a few people on completely stock bikes that have only done jetting that get 3rd-4th in B class

im bringing mine back to factory, and only going to use my yoshimura when im doing trail racing (for the spark arrester)

Share this post


Link to post
Share on other sites

hey guys just though i might add a bit of valuable input into the convo, i recently added a s1 hotcam a vortech ignition, ported head, yoshi slip on,je high com 13:5:1 piston and The backfire mod... after i made these mods i jetted it perfectly (it took alot of time :thumbsup: ) . now its scarily fast, i actually have to use throttle control LoL. seriously its worth every cent!!! its almost like riding a 450f with less torque.

by the way go yoshimura for 05 crf i have tried dr d and all the others and nothing compares to the yoshimura. BIG GUN INCLUDED!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×