ORIGINAL: estradajae
I bought mine in england for the exact price too...
Bushing bearings on camshaft is not only on thunder tiger.... I've heard Saito uses bushings there...remember the cam rotates half the speed of the engine.
The Bushings I think are not easy to remove if they can be remover at all...you'll have to mill the crankcase and the cover to accomodate the bearings....but I would bother neither.
I've tried the 12x7 and yes, the engine does rev more....but I don't see the point running the engine with a prop that a 75 2 stroke usually spins.... I would load the engine more.
You are falling victim to the confusion most folks experience with glow four-strokes. You are assuming (my guess - no offense intended) that the four-stroke glow engine will produce more torque than an equivalent sized glow two-stroke engine. In most instances, the two-stroke engine actually has "more torque" when allowed to spin the same prop as a four-stroke glow engine running at its best prop size for power production.
No, you're not crazy. What is confusing most folks is that when trying to choose a two-stroke glow engine displacement size equivalent, they must increase the four-stroke glow engine's displacement by a factor of 1/3rd more displacement, just to stay even in power production. Now and then there are a few exceptional engine models in both two and four-stroke designs that might tip the scale slightly in the opposite direction, but these are aberrations and do not upset the relationship significantly that I have described.
Ed Cregger