Basically it was the bottom end of the motor that came with my trueno. Engine ran perfect for ages. One day it started to chew through some oil. I wanted to put a 100kw in anyway (was twin carbs), so i pulled the 86kw out and dumped the 100kw in. I pulled the head off the 86kw and found the head to be in pretty bad shape (pitted valve seats, crappy stem seals). So either the bottom is still good , or possibly worn oil rings. Anyone is welcome to come have a look . The bores aren't scratched or anythign, and no holes in pistons.