As a play bike ok, as a mini racer NO WAY its way to slow to ever keep up w/the stock 150r even if the 150f is built. that said here are some simple mods pipe,air box mod or removed, rejet carb, rev box, and coil are the bolt on mods w/o motor work.
Ya not looking to make a racer out of it, it's the wife's bike and it sits around to much. I was thinking about making it into a fun little bike to play on, but as a stock setup it is really slow and softly sprung.
I beat the hell out of one for two years as my dirt play bike. We race XR100s and similar on a small roadcourse style dirttrack. The 150 was a dream, didnt do anything wrong and was indestructable. They can be made to make some ok hp. Mine had a stage 1 cam, crf carb kit with air screw. gutted air box, slip on FMF, lightly blended the boot to the port and it made 14 hp on my dyno. Id bet with some compression and a stage two cam and something other than 87 pump it would be getting close to 17-18, but will never have the violence of the 150 R. I put a steel line and good set of pads on the front, BBR springs and a BBR linkage to raise the rear an inch. It was great and a blast. It does seem heavy for what it is. I cant think of anything else it needed. The disk front worked well, and the rear drum was surprisingly powerful and consistent, for a drum. get a small chain and sprockets on it. saves a lot of rolling resistance. The stock shock worked well even at my 235 lbs, though a few a circle of fuel line in the shock spring will help with the added forces of pavement.
