So.. I got bored and built one of these
ended up with a 4 stroke motor (had my choice of 2 or 4, went with 4 since I would probably forget to mix oil after the 4th margarita)
The thing seems to run ok in the "weed wacker" orientation, but as soon as I put it up on "margarita" orientation it doesn't get full rpm...
any specific reason why a 4 stroker wouldn't run as good standing up ?