OK so it's not the only engine used in SPA events, but darn near. Why? I can understand using four strokes, but Saito weighs less and has a bit more power. Why do I hardly see it used? Magnum looks and weighs the same and the latest ones have more power. OK I know pattern guys would not be caught dead with a four stroke that cost less than $200, but the Magnum would do as well performance wise. Also there are a few .60 two strokes that at least come close to the same power. Such as the Webra, HP, K&B twist, Fox, Tower,etc. Also many others that have the same power but weigh more. OK I know the pattern guys are not enamored with the Fox, but it would be a contender if properly set up.