Hello sides7,
I just seen your question and something came to mind. You can convert Homelite 33cc bandit chain saw very easily and have much power then a 31cc Ryobi. A neat idea that I had for reverse rotation is to have a hub made for the tail shaft of the engine. This will give reverse rotation with the engine mounted with the flywheel in the rear. No modification of ignition is necessary and you can use the stock flywheel and coil. The engines will mirror each other also, with both carbs inboard etc. My 33 weights exactly four pounds with muffler. Best the saws are $99 each at homedepot brand new.

Regards, Dave