Top end doesn't seem to be a problem. I'm spinning close to 7500 rpm with a mejzlik 22-10. I have ordered a beila 24-8 and that should be about the perfect prop for it. I am running polaris full synthetic racing oil at 70:1. Everyone in my area is out of amsoil right now. I doubt that would have a big effect on the midrange anyway. I am going to try to tune it out thru the carb first, but i'm sure I'll have to end up getting the intake from 3w. I'm just alittle frustrated. I don't understand why you have to make mods to an engine that should just run the way it comes from 3w. Thanks guys keep the comments coming I'm sure there aren't too many of these engines out there, if this is how they all are.
Al