Well I shaved a New (woo woo! CHROME) slant head down and rejetted a different carb I put on the Kulana, I had ordered the new head from BGF because I wanted to replace the low compression straight plug head that was on that engine.
After replacing the head and rejetting the carb I got 41MPH out of it, but I think bumping the compression up on that older engine over stressed the wrist pin bearing because I have a jittery sounding rattle on top of the engine now, I was a little leary of bumping the compression up that much on the older engine and I guess my apprehension was warranted now that it has a rattle on top, it ran good at first but after about a 7-8 mile round trip I noticed the rattle starting up on the way back home and it had gotten worse by the time I got here.
So, I just got done ordering another top bearing along with a new wrist pin, I also ordered a new jug and piston & rings just in case I find another problem when I get into it, I know the noise is right up top so hopefully only need the top bearing replaced.
wish me good luck on it, just an old engine that has lots of very hard miles on it, I got this engine used and it looked like it had been abused so it was needing a bit of TLC anyway, so I'll get-er freshened up a bit and hope for many more miles of good service out of-er.
the pics show the difference in the combustion chambers old verses new that I put on engine compression is really bumped up now.