04 Yz 250 ? Big Bore Or Replate?

[BROGERSJR]

LAST CROSS COUNTRY RACE IT SUCKED IN A A LIL SAND ? Well anyway it welded the sand to the top of the piston and broke a ring . nice ! not much as far as scratchs but it looks like and smells like rubbing compound was applied to a motor at 13000 rpm . yeah . so the question is to go to a big bore ? 265? or have my newly wider cylinder replated/ I have seen yall talk about resleeveing and not many of you like that idea so who would yall refer for big bore kits and or replating cylinder ?

 

[CBRob]

What about the bearings that were exposed to the sand?
It would suk to rebuild the top and then have the bottom go out on you. A crank rebuild may be the safe route.

 

[geraldo]

Last time it appeared something was welded to the piston my main bearings were screwed. I would defiantly look at the bottom end since you were in sand and all. It could have sucked something up.

 

[Pete Payne]

Big bore it to a 2mm oversize , with having the cylinder replated to the 2mm oversize .
step 1 Overbore cylinder 2mm , step 2 port cylinder , step 3 have cylinder raplated ,
step 4 machine head to work with overbore. step 5 clearance powervalve's to work with new bigger piston. Step 6 rebuild bottom end step 7 assemble all parts and be glad you don't have a 4 stroke !

 

[BROGERSJR]

YEAH. I have already ordered bearings for lower end. So 2mm oversized? and replate? What does that mean in terms of size piston? Isnt that the max size on original piston that i could get ? It almost sounds cheaper to order new cylinder and have head work done to it.
Thanks for the advice

 

[Pete Payne]

That would be 68.5mm wiseco part #804M06850 . New stock cyl with porting might be a touch cheaper but it would not hold a light to the 2mm over cylinder .