what is a better piston

[mxman107]

wuz-up everyone i'm rebuilding my top end would to know what would the better piston to use pro-x or wiseco pro-lite.on a 97 cr250r

[AJ_YFZ]

Welcome to .... I always use wiseco pistons with no problems.... Just depends on how you maintain your bike really

[mxman107]

the things is i just rebuilded it fresh plate jug wiseco pro-lite and i let my brother ride he mix gas ratio to 32:1 and it melted my piston.

[kschilk]

Originally Posted by mxman107

the things is i just rebuilded it fresh plate jug wiseco pro-lite and i let my brother ride he mix gas ratio to 32:1 and it melted my piston.

Last I heard, Pro-X is Wiseco. As I understand it, the Pro-X is more similar to stock.

[mxman107]

pro-x is a cast and wiseco is forged

[dogger315]

gas ratio to 32:1 and it melted my piston.

32:1 didn't melt your piston. You obviously have another problem
if you are melting pistons with a normal fuel oil ratio.

dogger

[mxman107]

do you have any idea's what could be wrong maybe didn't back it in right.

---------- Post added at 11:38 PM ---------- Previous post was at 11:36 PM ----------

i still think it was lean, bike didn't smoke after running for 10 min

[mrcribbs]

Probably an air leak.

Air leak = lean = trashed internals.

[mxman107]

does anyone live in fl and ride a 2 stroke and if so what size main jet are you running?

[Woody_YZF]

I think they're both decent pistons. I personally have had great success with Wiseco for many years, but Pro-X has been good to me on other products, such as seals, bearings, etc.

[mynewcr250]

Originally Posted by kschilk

Last I heard, Pro-X is Wiseco. As I understand it, the Pro-X is more similar to stock.

actually from what i understand the pro-x is a surplus oem piston. they are all made by ART which is the oem supplier of pistons for the bikes. it is a cast piston.


i personally like wiseco. im running it with my cr250 and it works great. on a brand new piston and jug that were fitted right and proper ring gap was set, if you melted a piston i would say you have an airleak. an air leak will allow more air to enter AFTER the carb which leans out the mixture. lean mixtures cause excess heat, and you know the rest. id say a pressure test is in order. i did this with my 2000, used moly 60 grease for the pv linkage and it held 6psi for well over 10 mins. i went to in n out came back (you know how long the lines are at in n out if youve ever been there). id say a good thirty minutes later, i was down to a little over 5.5psi. pretty damn good and something i think everyone should strive for.

[dogger315]

i went to in n out

You're making me home sick.

Good information about sealing the power valve. I'm guessing it's
more than that in this case. To actually melt a piston that fast -
it would have to be wopper leak. Since he just finished the top
end, I'm thinking reed cage or cylinder to case (possibly a mis-
alligned upper to lower power valve shaft). In any case, a leak
down test should provide the answer.

dogger

[mxman107]

thanks guys i will do a leak test after i put the new top end on.what do you guys know about the two hole in the piston on exhaust side.

[dogger315]

what do you guys know about the two hole in the piston on exhaust side.

Not applicable for your motor. Just install your preferred brand of piston,
button everything up carefully, perform a leak down test looking for a loss
of no greater than 1psi/min.

Let us know what you get.

dogger

[mxman107]

will do it will be about 2 weeks.