[Masteryota]

Well, seeing as the yerf did not come with reverse, I'm not heart broken about it. Using a separate gear box to add reverse would soak up too much hp, if that engine put out around 20 or so, it wouldn't be so bad. If I decide to add reverse later, it will likely be a starter and flywheel style mated to the jack shaft, but thats like very last on my list of things to do.

I heard the same thing about the xr200, and the 200x cam, but all the specs I have found indicate the power gain is marginal, and its all in the top end, I want the low end grunt for mine, part of the reason I did not opt for a sportbike engine. I almost bought a complete ninja 250 engine for this thing, but the power doesn't come in till after 6k RPM.

Bumping the compression will increase power throughout the entire RPM range, but you have to be careful about heat, increased compression will result in more heat generated. I plan to use a 14" radiator fan behind the seats to help cool it off.

I did look at the Wiseco pistons, but at $120 for a piston, and the likelyhood of breaking the recoil rope on the trails seemed too big of a risk. The stock runs at 7.6:1, the x model piston runs 9.6:1, the race piston is 10.25:1.