RE: 90 sized engine recommendation
Your experience with that company must be better than mine. I bought a 50cc gas engine from Tom Johnson at the AMA convention on the 9th. He said it would ship on the 11th. On the 20th I called and they gave me some story about replacing the carb blocks. I've tried calling for the past two weeks and don't even get someone picking up the phone. Same with numerous emails to them.
Frankly, I'm NOT impressed with them and will probably have to take legal action to get my money back.