Just picked up a old\new built Super Sportster with a ST 2300, the old one from Italy. The planes never been flown, and the engine has never seen fuel. I was told 0-5% only, but I read here that quite a few of you use other. Also, I think this one has the "dogleg" groove in the barrel, so I am looking at replacing that. But what was the problem with this carb design?

Thanks, Greg