How much more power is possible

If you start with a stock wrr what is the max power with all the goodies fitted can you achieve what would be the power percent increase and what would be the cost and would it still be reliable

What do you mean by "all the goodies" ? Are you talking about the standard mods, or big bore kit / turbo ?

lanerider wrote:

If you start with a stock wrr what is the max power with all the goodies fitted can you achieve what would be the power percent increase and what would be the cost and would it still be reliable  

First off if you are asking that question you may want to look at another bike. Power is only part of the equation and I would probably value suspension over power. That being said I think money is better spent on suspension before power.

Now back to your question.

I suspect that most people pick up anywhere between 10 and 20% with the standard mods - open up the airbox, performance exhaust, and some type of engine tuner (FMF, Power Commander, etc). However the best improvement per $ spent in my experience is to change the sprockets on the bike to better utilize the engine's power curve. This engine likes to rev and in it's stock gearing is just too high for most of us.

Some people have installed turbo's, overbore, and stroker kits - maybe some one has done all three but I haven't seen it yet. The biggest benefit from the overbore kit is the beef up the power delivery down in the lower RPMs. I have heard horsepower numbers in the low to mid thirties with an overbore and stroker kit.

Reliability after doing all this is a good question. Some of the overbore kits people have seen their engine fail in less than 2000 miles although one can argue that it was not properly set up and tuned. I would imagine though that if you take a motor generating HP in the low to mid 20's and bring it up the the low to mid 30's you are probably going to have issues with the clutch and drive train at some point. Just a supposition on my part.

For most of the bolt on stuff (exhaust and fuel tuners) I don't think the bike reliability is degraded unless one does not set up the bike properly - like using a fuel tuner when installing a performance exhaust and setting the tuner properly. I think most of the reliability concern here has to do with the bolt on products themselves (documented issues with fuel tuners, bad rivets or welds on exhaust components, etc).

it looks like it could be never ending gaining a few hp here and there the reason i asked this question is to understand what can be achieved from a bike that I'm very happy with in stock form ...o and goodies is a uk word for the bits you add on to make a improvement to stock i use 13x43 sprockets so i can cruise at 70 with out pushing the revs the bike is in stock form to keep reliability if i use on technical dirt i use 13x51 and full knobbly tyres the wrr is a full on duel bike that can be adapted to all running conditions but curiosity made me think if i had the money how much power could be achieved from a 250

turbo kit = around 40hp

bang for your bucks

Search the Internet with "WR250R dyno chart", and you'll have some reading.

Stock is 21 RWHP, Believable numbers are up to 25% or 26hp with pipe, air box/cleaner mods & proper tuning.
up to 50% or 31HP with a big bore kit, up to 75%  or 37hp with a big bore, stroker & ported head.
SSW claimed 40Hp or 90% with a 306cc, his porting, camshafts, K&N filter, air box door removed.

I assembled the combination in blue. I have not put it on a dyno, my butt says it's at least 35hp.


Best bang for the buck if you want more power IMHO is the Thumper Racing 280 kit.