Messages

1

Technical / cylinder''''s head modification for overbore

« on: November 03, 2012, 12:03:25 AM »

thks for the reply!

and for the head gasket? does it need to be the exact same diameter of the cylinder ? since bore is 2mm bigger now, i figured that the gasket will be like 1mm all around inside the cylinder? do i need tu cut out the interior a little?

2

Technical / cylinder's head modification for overbore

« on: November 02, 2012, 08:35:20 PM »

hi! i have this little rm80 1986 that i picked up for my girlfriend as her first bike.. it need new piston and it looks like the cylinder needs to be bored. Std bore is 47.5mm and right now it is 49mm. So i've decided to go with a wiseco 49.5 piston kit. i have to say it is my first to end job. Some people say that the cylinder's head needs to be modified when overbore is made, as well as the head gasket, to prevent from a too high compression ratio. Is this true for any application, or in my case, should i bring the head with the cylinder to the machine shop? thks and sorry for my bad english