Puma 250R's

I thought your Puma had already been dyno'd at ~90hp or so.....

I am wanting to put one together using the 137.5mm rod on an 85 bore and 76 stroke. But I gotta wait a bit more.....

Part of me still want to do a smaller motor with a powervalve, but I like the idea of the 431cc Puma. Even a Saber is tempting.....

Sandtrix, I appreciate your views on big single cylinder Hondas. However, we don't run knobbies, we run flattrack tires on oval and TT courses. Coming out of the corner on these tracks is quite different that coming out of the hole on a drag race. A lot of the time your engine rpm is dictated by how tight and twisty the TT course is and this sometimes means that coming out of the corners you're really not in the best part of the power, no matter what gear changes you make, especially when you take into consideration the gearing you need on the longest straight.

As you are well aware of, I'm sure, the 4 strokes make real good torque down low (most of it is in the lower rpm's). The 4 stroke power is very tractable and makes for very good corner speed and excellent corner exit speed (corner exit speed is where it's all at in this form of racing in my opinion... as most passes are made coming out of the corners....)

What I think could be done with a power valve is hopefully make more power/torque where it would be beneficial particularly on tight technical tracks. Most flattrack/TT bikes would be overkill with 90+hp unless the track is a big 3/8 mile oval (they don't run those much anymore...)

Here's an example of what the small 265R has to face. Granted it's more a best case (ain't too many thumpers putting out this power in the flattrack/TT ranks).

If you're coming out of the corner at 6500-7000 RPM, that 4 stroke done run off and left you......