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What piston for rebuild??

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Just wondering what piston you guys recommend for a 06 motor?

Probably going to do new valves and springs at the same time.

Marco

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in my opinion, i would go with OEM engine components.

your options would be the stock compression 12:1 piston (this is the one i would go with)

or you can get an 08/09 13:1 higher compression piston (i like to rev my bike so i like the lower compression piston) you can still run this piston on 91 pump gas. give you a little more umph on bottom.

or many people have had good results with the forged JE 13:1 high compression piston which you can purchase from the thumper store.

and for you head. check to see if your intakes are bedding into the head. most commonly the right intake will be the first to bed. if it is then i would get it redone before you botton up your engine again. good luck!

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Cp......

If you buy a Moose, it's a CP in the box. That's all I use for my kids bikes. Quality is incredible! So are the JE's.

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Who are you guys buying the CP from?

Anyone that sells moose products which is a lot of places.

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For the 2004-2007 crf 250, get the Wiesco RC804M07800, it is the race series 13:1, it is a really good quality piston with a lot of good characteristics. They are way better than oem. It is boxed forged, shot peened, titanium nitraide coated rings, ArmorGlide permanent skirt coating, super finished wrist pin, improved pin lubrication, and dome edges are smoothed.

I admit my son is sponsored by Wiesco, but we were using these pistons before we asked for Wiesco's help. Would be using them without their help. I bet these pistons are used by more good motor builders than any other piston.

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CP pistons.... hands down....

wiseco has made the worst pistons the industry has ever seen...

they have only upped their game in response to JE and CP making way better engineered products...

if it werent for je and cp... wiseco would still be selling "bricks with piston rings" and sewer pipes for wrist pins....

fact

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You guys are brutal. I happen to disagree. Wiseco is the only aftermarket piston manufacturer in the USA that forges all our own pistons in house. That gives us the ability to make very optimized designs for each piston application. There is no excess milling on the bottom or sharp edges to cause stress risers. Flip over a CP piston sometime. Their late model stuff has fine forgings, but notice a lot of their parts have a lot of extra milling on the bottom since the forging was not optimized for the original design. We also apply a permanent skirt coating in house - the other brands mentioned do not. We have in house engine dyno's for product testing, validation, and new product development. The other brands mentioned do not. I would challenge those comments that say our products are not on par or exceed the other forged brands out there. If you had a bad experience with your piston in your 2T 20 years ago, I would encourage you to give us another try - this is 2011. We have more piston models than anyone else in the aftermarket. Hope that helps. www.wiseco.com www.facebook.com/wisecopistoninc

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Im sure Wiseco is a great piston as well as JE but i'm going to try the 13:5.1 CP this time around...getting a decent deal from my dealer so cant complain

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I have used Wiseco for years as my first rebuild choice and they have never failed me. With that said, I just ordered a 270cc kit for my '09 from Venning and it will have his custom design 14.5:1 piston made by CP. Since I race at 6000 ft. Elevation, this piston will get me close to 12:1 (air is about 20% less dense at this altitude) so I can still run premium pump gas.

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You guys are brutal. I happen to disagree. Wiseco is the only aftermarket piston manufacturer in the USA that forges all our own pistons in house. That gives us the ability to make very optimized designs for each piston application. There is no excess milling on the bottom or sharp edges to cause stress risers. Flip over a CP piston sometime. Their late model stuff has fine forgings, but notice a lot of their parts have a lot of extra milling on the bottom since the forging was not optimized for the original design. We also apply a permanent skirt coating in house - the other brands mentioned do not. We have in house engine dyno's for product testing, validation, and new product development. The other brands mentioned do not. I would challenge those comments that say our products are not on par or exceed the other forged brands out there. If you had a bad experience with your piston in your 2T 20 years ago, I would encourage you to give us another try - this is 2011. We have more piston models than anyone else in the aftermarket. Hope that helps. www.wiseco.com www.facebook.com/wisecopistoninc

not a bad experience.... endless bad experiences....

lets talk a bit about overbore pistons... why would you offer an overbore piston kit for a machine...say an xr 400... that weighs a whopping 46grams more than stock??

it is a full width casting with a full width sewer pipe wrist pin.... and the weight is enough to put the crank balance off...not to mention the performance downgrade...or component wear...

i have been building 2 and 4 stroke engines for over 30 years and my fingers would wear out if we were to go head to head on where wiseco pistons built its company on endless overbore options instead of performance engineering

brilliant for business... but not the performance business

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I have used Wiseco for years as my first rebuild choice and they have never failed me. With that said, I just ordered a 270cc kit for my '09 from Venning and it will have his custom design 14.5:1 piston made by CP. Since I race at 6000 ft. Elevation, this piston will get me close to 12:1 (air is about 20% less dense at this altitude) so I can still run premium pump gas.

fyi... buy a lot of modeling clay to stuff around the crank... there is a lot of material that needs to be deeply cut towards the crank to fit those cylinders into the cases...the clay sealing everything will be the ticket....vacuum the hell out of everything when done cutting....and then put a thin layer of more clay over the particles stuck to the clay...sort of an aluminum shaving oreo...before you pull the clay out

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ordered a new timing chain also...debating if I should do cam and valve springs now :smirk:

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