I am starting to look forward toward building a .60 flier. Probably a Sig 4Star. I am thinking about putting a 4 stroke in it rather than a two stroke. Something around a .91 or so. Herein lays my question. There are several manufacturers of 4 strokes and within most of the manufacturers there are a couple different choices of engine at the same (close) displacement. To name a few, OS, Saito, YS, Thunder Tiger, etc (?). Then there is ringed vs. non-ringed. I can't say cost is not an issue, but it will not be the main issue in my decision process.

Any info regarding comparisons of any/all 4 stroke fuel engines around the .91 size will be greatly appreciated.

Thanks,

Roy