Well, the
Tecumseh TC300 is the only 2-stroke engine that Small Engine Warehouse carries. I haven't heard much about it, as far as reliability goes. It costs 110, but, you need to add in another $16 for the clutch.
I see that it has a non-standard clutch mounting arrangement, but SEW carries two clutch sizes to fit; a 2 inch, and a 2-3/8 inch. The two inch is 50.4 mm, so it
may mate up with a 54mm standard clutch bell. The 2-3/8 inch clutch won't mate up with anything standard. The standards are 54mm and 78mm, with the 78mm clutch being MUCH more common.
SEW doesn't state the bolt circle size or thread pitch on the engine, so you'll have to do some digging to find out if it's the same as on the 25cc engine class (Honda GX25, Mitsubishi TLE23, the R/S 25cc, etc.
Staton sells a friction drive kit, with the 54mm clutch, and possibly a chain drive kit (less motor) as well. I don't know if BMP offers their kit in the 54mm clutch.
However,
here's a decent alternative, although it costs about $160 - the Mitsubishi TLE33. IMO, you can't beat the genuine Mitsubishi for a quality two-stroke engine. Plus, it burns clean without a catalytic converter, and it comes with the 78mm clutch installed.
There are outfits that sell 40cc+ mitsubishi clones (of older TL series, that is) in the 140 dollar range, but, their quality is hit or miss. "You roll the dice, and you takes your chances..."
How are you thinking about mounting the engine? Rack or in-frame? If you're not going with a friction drive, you need to reduce the engine RPM by a lot before it gets to the rear axle, the Staton gearbox is about 18:1 reduction.
