2-strokes-4-life
Member
- Mar 1, 2005
- 231
- 0
the piston i recently pulled from my cr60 has a black spot under the crown.i thought it might be burnt on oil but if i scrape at it with my fingernail it will come right off and underneath it looks fine.could it just be carbon under there?im hoping so since the piston looks great otherwise.i imagine since the crown hasn't even become completely covered in carbon and i can sill read the oversize number stamped onto it, that this top end has not been in the motor for very long.but i bought the motor used off that auction site so i dont really know how long its been in there.i would really like to reuse the piston if possible since i cant get this size for it anymore.also the cylinder walls have some rust colored stuff on them,my dad said it could be burnt on oil but im not sure. other than that it also looks great with no scuff marks at all.also when i put it back together do i have to use a torque wrench?reason being is at this point im kinda broke and we dont own one i remember year ago i rebuilt a motor with my dad not using one and cant remember any problems,just thought i'd ask.any input will be appreciated