thanks Fandatstick its looks like it could be it im going to go out and do a comparison. i did say this engine was supose to be a gx1200 but im starting to wonder, the hitachis are square top as well and after reading wiki thats not gx1200? i wonder if the head with heart shape chambers and same double valve springs as gx1200 is actually off something else? with this crank as well that makes this engine what?-ta