[250r 425 psi engine] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

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250r 425 psi engine
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Posted by: skyhigh716

I have never really checked into the whole powervalve motors and the 425 psi motors, but I hear that they both rip. I am looking to purchase one or the other in the near future, and would like for someone who knows a little about them to maybe tell me the difference between the two. Maybe even some pros and cons. Thanks in advance,
Dustin

Posted by: zedicus00

http://www.saberracing.com/

Posted by: wilkin250r

The PSI 425 is 425cc, and it's an actual, specific engine kit from a specific manufacturer.

A "powervalve" isn't a specific engine kit. A powervalve is a special part that goes on the exhaust port. It can be made in a variety of displacement sizes, and many different aftermarket companies make them.

A powervalve doesn't make your motor rip. In fact, it makes your powerband very smooth and mellow, which gives better traction coming out of corners, and is generally easier to ride. A powervalve cylinder generally isn't any faster than a non-powervalve the same size, it's just easier to ride.

Posted by: 86-250Rnut

So the psi of your engine is your displacement or cc?

Posted by: Hoppedrap

quote:
Originally posted by 86-250Rnut
So the psi of your engine is your displacement or cc?

No! PSI is a company that manufactures aftermarket parts, including a 425cc top end for the 250R

Posted by: zedicus00

but if yur engine has 425 psi, i dont think even race gas is going to help u.

Posted by: wilkin250r

quote:
Originally posted by zedicus00
but if yur engine has 425 psi, i dont think even race gas is going to help u.

With that kind of compression, you could probably run on butter, but jetting would be difficult.

Posted by: Hoppedrap

Could you imagine trying to kick that SOB, I have enough trouble with 190 PSI and my 76mm piston

Posted by: Iliketogofast

Jesus christ... a +40HP bolt on.

Posted by: 330EXman

just a note

if you get this all figured out aand what you actualy want i will say this

PSI makes some badd *** engines and im tellin you they got alot more high tech advances then other do on the market. like psi uses a kickass 12 port layout in there cylnders more then anyone else. i run their engines and love em i just talked to brian over there and he's gettin ready to send me out a 350powervalve but if you gonna ride this thing daily you dont really want to go over 350cc and powervalves are very nice and help make your motor run smooth and strong from bottom to top end while a non powervalve engine power comes in a wave called a powerband and this hit hard and at certain points and in order to ride and ride fast you have to learn to keep it in this powerband and this makes it aggrivating to trail ride powervalve are the way to go

good luck there are many other good 2-stroke builder such as LRD, CT, and sparks and cant forget sabber racing but choose carefully and dont choose anything that you cant handle