RE: 90 sized engine recommendation
Get an O.S. Engine. You'll be glad you did.
If you want an engine that's harder to tune, get a brand other than OS.
If you want an engine that dead sticks on you in the air, get a brand other than OS.
If you want an engine that won't hold it's value if you ever want to sell it, get a brand other than OS.
If you want bad fuel economy, get a brand other than OS.
Just my 2 cents.
I really like it when I fire my OS engines up with 1 or 2 flicks of the prop and get my plane airborne and other are still fiddling on the ground trying to tune theirs with their cheap engines they have on them.
That's about like driving a rolls royce with a old beat up ford motor in it just cause you wanted to save money on the motor.
big dan