whats causing this ?

[Drifz1]

Hey you guys have any idea what would of caused this its of my kx125 , i think it may be the powervalve hitting of it ,it must have a bit of play

 

[Antec1200X]

must be the power valve.
i havnt had my kx's top end off yet but plan too as soon as i get an excuse.id like to redo the top end and do some porting

 

[blasterkiidirl]

Hey you guys have any idea what would of caused this its of my kx125 , i think it may be the powervalve hitting of it ,it must have a bit of play

it could jst be ware and tare i no some dat race's a rm125 and he blew 2 engines so far and he only had since the start of th year

 

[Drifz1]

nope its done it twice ,on my new piston also but not as bad on my new one

 

[Luni]

Ill bet its your powervalve. Same thing happened to my buddies RM250. Powervalve broke, got stuck, piston was hitting it, was impacting the rings, no bueno.

Sucks too cause those powervalve assemblies are usually expensive as balls unless you can find a used one.

 

[Antec1200X]

maybe this will help before you install a new piston
http://www.wiseco.com/PDFs/Manuals/MSeries.pdf

 

[Drifz1]

thanks for the help guys opened it up today and you can see the marks on the PV where it was hitting might just file it down,thanks

 

[OConnor Racing]

Grind .040" off the front of the flapper valve.