Hello; I like Saito's, I have a bunch of them; 45, 50, 56, 65,80,91,120 30, 150, 3 80's 3 65's, I have a 100 twin too, They are great engines, they last forever run well make good power and are very flexible easy to start and run quiet and reliable, not fuel fussy either. I also have quite a few Os and Enya 4-strokes, they run pretty well too. My best running engine is an Os 320, it is an opposed four cylinder engine. On the other hand, two fellows at our flying field recently bought OS 70 engines, one was a jewel the other a dog, they both went on similar planes Sig LT40's. We have the dog performing better now after a gallon of fuel, but it still isn't as nice as the other one has been from the start.