[Bootypatrol009]

what would give my 05 CRF more hp...a new header or silencer? and what kind should i buy?

[Asmith]

what would give my 05 CRF more hp...a new header or silencer? and what kind should i buy?

Have you done any rejetting yet? That's where you'll find some power increases. The header, like a FMF PowerBomb, will give you some low end torque increases.

I don't think you'll find a big increase over the stock R exhaust. Alot of us guys run the R set up on our X's because it's so good.

Dobent4 has a 450R and he's running an Akrapovic system on his bike and he loves it.

Try PM'ing him, he can give you more details on where the power increase are.

[KevinM]

As another option after you do some other mods....White Brothers will turn it into a 307cc fire breather.. for $2750

adds about 9 hp.

If you're in an open class like 30+ or 40+ and have the cash.. and don't mind sending them your engine.. that might be the ticket.

I'm giving it some thought for an R I'm about to buy.

[JAWS]

Yeah, but if you take that money and sell your 250R and buy a 450R then you will have all the horse power you'll need!

Joe

[KevinM]

Yeah, but if you take that money and sell your 250R and buy a 450R then you will have all the horse power you'll need!

Joe

You are correct sir. And then some ....by probably 7 or 8 HP.

Actually, the reason I'm thinking about it is I'm pretty sure the 450R will be too much for me to handle on the track. (I'm a novice). If after I've ridden the 250R for a while, I decide I need a little more pull, the 307cc bore seems like a middle of the road option without having to sell my 250. Ain't cheap though.

Odds are, I'll leave the 250R alone but the 307 is interensting to me for a few reasons. One more was weight.

[Bootypatrol009]

yea my dad has the 450... ive only drove it a few times...we normally do trail riding and on the straight aways and he can only walk away from me. Not a big difference in top speed but off the line he puts me to shame

[JAWS]

Yeah, but if you take that money and sell your 250R and buy a 450R then you will have all the horse power you'll need!

Joe

You are correct sir. And then some ....by probably 7 or 8 HP.

Actually, the reason I'm thinking about it is I'm pretty sure the 450R will be too much for me to handle on the track. (I'm a novice). If after I've ridden the 250R for a while, I decide I need a little more pull, the 307cc bore seems like a middle of the road option without having to sell my 250. Ain't cheap though.

Odds are, I'll leave the 250R alone but the 307 is interensting to me for a few reasons. One more was weight.

Weight is a factor, but not as much as you might think. The power of the 07 450R is very controllable, not like a few years ago when it hit like a two stroke. On tight tracks, the 250 is just as quick as the 450 and quicker in some places, due to weight, not spending as much energy in wheel spin, and other factors. They are still close.... very close. Try to find some friends that will let you try their 450 and see for yourself, keeping in mind that the 07 has mellowed just a bit.

Another issue with the 307 is that there will come a time that you want to sell it and you may have trouble finding a buyer with such a highly modified bike.

Good luck,
Joe

[KevinM]

Thanks Joe. That's good info.

I'm hoping I can take a spin on 450R at some point. Part of me says, if I don't hammer it when I don't need to, I wouldn't have a problem. Then another part of me reminds me that I've never ridden a 450R and have no idea what I'm talking about.

A guy at a dealership near me said I'd be fine on a 450 and I could probably ride the whole track in 3rd gear whereas on a 250R, I'd be shifting a lot more. Essentially, making it a bit more work to get around.

Decisions ...Decisions...

If I can't get a ride on a 450R I may end up with 250R, but I'm pretty convinced that when it comes time to replace my '05 250X..I'll go with a 450X. If I ever regret it, I can always sell it and go another route.

And re: resale of the 307. That's a good point. Thnx again.

-Kevin

[Asmith]

Kev,

As someone who has just made the transition from the 250X to the 450X I can tell you emphatically...do it!!

If you are scared of your 250X, stick with it. If you are wishing you had more grunt, there is no cure like a 450.

The bikes are very similar, so the learning curve is short. A little more weight, but not too bad. Just don't ever ride the 250 again and you'll never notice it.

The power difference is worth the price of admission.

Joe is correct, the 450 it is...

[MX Fred]

what would give my 05 CRF more hp...a new header or silencer? and what kind should i buy?

instead of a pipe this should be cheaper and give you better results. Go with a 07 head (with 07 valves) and 07 cam. If you can afford the extra $$ go with a JE pistoin 13.5:1. You'll still be able to run pump gas but must use premium.

You will be a very happy person!


06 CRF250R
05 CRF450R (60HP!)
RHC ported head and valves
RHC187 Cam
JE 13.5:1 piston
DMC Exhaust