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  

  • Similar Content

    • By Callum Hunter
      I'm quite new to the moto scene and I've got a '09 CRF250R in need of what I believe is a top end rebuild. I've never gotten a rebuild before so I'm unfamiliar with the process and the steps to take in getting this done in a safe and efficient manner. I was wondering if anyone knew of any reputable shops in or near Vancouver, Canada (where I live) that could look at my bike and help me out with my situation. About 6 months ago I got an inspection on the bike and the shop told me that my cam bearings had "spun in their journals", requiring the installation of a new cam along with the rebuild. I haven't had anything done to the bike since the inspection so the motor is still in this state. She's running but I'm afraid that the motor is a ticking time bomb and would like a shop to take a look at it, let me know what needs to be replaced and get the rebuild done without me worrying about getting taken advantage of. I'm currently out of the country in school but have plans to get this done once I'm back. Any tips, recommendations, or help would be greatly appreciated!
    • By Kadensmith44
      I’m wanting to powder coat my bike but it’s all new to me. I’ve got a powder coater picked out that I’ve heard is good for what I’m doing. I’m not 100% what kind of sand blaster I need and what kind of media. I have also heard you can’t cook in the oven after you’ve baked your parts is that true?
    • By luke8500
      Hi all, 
      I have a 2004 honda crf250r and it wont start hot at all. The motor was just rebuilt with a new cylinder and piston. The valves were just adjusted. It will start cold in 1 or 2 kicks with choke but as soon as it gets hot it wont start. If you bump start it the motor will just turn over without starting.  sometimes it will start. It runs great until you shut it off.  im thinking its either a fuel issue or an electrical issue. Any help would be greatly appreciated. 
    • By SandSoldier
      Hello! This listing is for my 2007 Honda CRF250R dirt bike. Last winter I spun the rod bearing and just recently finished rebuilding it. Selling to fund new bike. I am currently the second owner.

      Current registration valid until 2020, pink slip in hand.

      Fresh parts:
      -top end kit: Wiseco; forged, moly skirt coated, 12.9:1 comp ratio (new wrist pin, gaskets, etc)
      -cylinder: new OEM
      -bottom end kit: Wiseco; (new bearings, seals, etc)
      -oil pump: new OEM
      -head studs & nuts: new OEM

      -fresh oil and filter
      -all tolerances checked in top end
      -valves adjusted
      -carb adjusted

      Note:
      *rebuild was done by my dad (master tech at CAT) and I (4th year mechanical engineering student)
      *has maybe 15 minutes on new parts, IT HAS NOT BEEN PROPERLY BROKEN IN YET
      *I have email receipts, pics of rebuild, and old parts as proof of rebuild, just ask and I'll show em off

      Other parts:
      -90% tread on front and rear tires
      -excell takasago front wheel
      -custom aluminum skid plate
      -wrap around hand guards
      -spark arrestor
      -kickstand

      Feel free to ask for any more specifics or pictures!

      LOCAL PICK UP ONLY

      Thanks!
    • By Matt Ray
      Okay so the title is a little vague. 
      So it was having trouble idling and even starting when I first bought it about a month ago for $2k. 
      So I did a rough clean of carb, looked up on YouTube, Forums, Etc on how to do it. I only cleaned jets with carb cleaner and sprayed around the float bowl area and such, so not too extensive.
      Did that and I took it out to a park, It would start up right away mostly, few kicks sometimes, but when I got it started, I had to keep the choke on. Right when I was ready to go fast and go up to 3rd and 4th gear I'd switch it off and it would work fine and sound fine and everything, but when I slowed back down and coasted around 1st gear i'd pop it back out again because it sounded like it was going to do. I have some videos if people would like me to link to them.
       
      So after that I decided to take it apart and replace spark plug with OEM NGK R0409B-8, replace main jet from a old 170 to a new 170, replaced pilot jet from a old 40 to a new 42, and kept starter jet the same just made sure that wasn't clogged, ordered a new adjustable fuel screw and used that.
      and it was still having a little bit of problems! I just started up today and the day before today. It would run only with choke on, if i twisted throttle in neutral it sounded pretty good, no gun shot noises or anything, pretty smooth. 
      If I tried to take choke off it would die immediately. So I started it back up again, took around 6 kicks.. So again with choke on it sounded like it was starting to lose power and RPM's would drop so I'd twist throttle a few times and it would stay idling.. then after a small amount of time, start to sound like its about to die again... so I would rev it up again, and repeat..
       
      Fuel line isn't clogged, flows fine.
      I tried fuel screw everywhere between 1 and 2 turns out..
      I checked valve clearances, and I'm no expert but from the videos I watched the slipped underneath intake and exhaust with only minor force.
      So I'm lost.. 
      Maybe float bowl is messed up? Should I just do a COMPLETE carb rebuild from videos I've seen on youtube, like this one -> https://www.youtube.com/watch?v=3AXb9UprT30? Or what? 
       
      It's getting annoying taking it apart all the time, I jsut want it to start up quickly and run well!!
       
      Thank you!
       
      Austin, TX, Elevation 600ft, where I ride its around 900ft
       
       
×