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250 engine kit

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I have finally got the kxf on the dyno its promising curently im just over 41 hp and 20. 9 pounds of torque im using mr 11 for fuel if i had the mr 9 this bike would be making 42 hp right now .This was the most powerfull 250 stock on my dyno very close to 36 hp when i finshed the engine and put it on the dyno it started @ 38 hp i have been working with the exhaust system in 1" increments i found an interesting thing i found the length that made the most power and then added 1 more inch and it lost quite a bit so i added 1 more inch and the power shot up over my previous best its hard to beleive but 1" of exhaust header length can help or hurt the power .

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What RPM? Corrected? SAE J1349 or STP?

The hp is corrected to sae the hp peaks @ around 12200 rpm @41.3 the power also stays from 40 @ 11500 to 12800 rpm corection factor is .99

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nice number!

But im confused You say its the most powerful 250 stock and the test from transworld said it was the weakest in hp? But still said that it got a powerful engine.

Its weird the bike runs great so im not really worried about those numbers transworld got just curios.

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All of my test have been with nearly new bikes when i dyno them maybe when the transworld bike got on the dyno it was damaged .All of the components in the new kawasak add up and should make the hp i seen just based on the port flow and cam shafts they come with theres only 1 hp diference betwwen the new 250s that 1 hp feels like a lot by seat of the pants may be thats why a lot of the pros say a good 250 with 6or7 more hp feels as fast as a 450 .

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Ron,

Stop posting numbers like that, your making me jealous !!!

I love my 09 KX250F stock, and i'm probably not going to put much money in the engine, but what is the ballpark cost to go from stock 36hp to your modded 41hp ? 2k ?

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Ron, Jesse said he had trouble finding cams that worked better than stock, did you find this to be true also?

Did you bore the carb or try a different ignition?

The PC team bikes have very long headers for 09.

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Ron,

Stop posting numbers like that, your making me jealous !!!

I love my 09 KX250F stock, and i'm probably not going to put much money in the engine, but what is the ballpark cost to go from stock 36hp to your modded 41hp ? 2k ?

yeah im interrested as well...i have an 07 kx250f though

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Ron, Jesse said he had trouble finding cams that worked better than stock, did you find this to be true also?

Did you bore the carb or try a different ignition?

The PC team bikes have very long headers for 09.

The carb is bored i did 2 diferent intake grinds and kept my old faithfull exhaust grind that i have used in the suzukis i have the vortex ignition none of the curves show any thing on the dyno im going to work with my own custom map eventually.i have to be carfull here not to get to much power from theses kawasakis or my freinds from the big honda teams wont like me any more.

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All of my test have been with nearly new bikes when i dyno them maybe when the transworld bike got on the dyno it was damaged .All of the components in the new kawasak add up and should make the hp i seen just based on the port flow and cam shafts they come with theres only 1 hp diference betwwen the new 250s that 1 hp feels like a lot by seat of the pants may be thats why a lot of the pros say a good 250 with 6or7 more hp feels as fast as a 450 .

Might have been so since it won the test and it said that it had a great engine. But anyway i belive a enginebuilder more then a shootout and the bike really runs great to be a 250F so :)

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.i have to be carfull here not to get to much power from theses kawasakis or my freinds from the big honda teams wont like me any more.

I hear ya :)

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