Stumpalump - My tach is not working at the moment. So I'm not really sure the exact rpms. Think it just something in the wiring , or may just need to replace. I've not tackled that yet lol but the carbs are a low speed adjust and high speed fixed. They came with the motor and have worked fine unless they've gotten dirty or in need of a rebuild, no issues with otherwise. Like you said, it's a great motor and runs great when no issues going on. From what I've read on the 48 sp it was Johnsons "work horse" (for commercial) boats. It surely has good pull, and the top end on it is great too , plenty for my pleasure fishin. I dont use it for pulling or sking, just fishing. It wants a lot of gas on a cold start, but after get it warmed up, is idles great and will idle all day if I let. Been really happy with it. The air box has 3 holes that are quarter size, maybe little bit larger. And I was a little worried about justing drilling some extra air holes, not sure if I would be masking another problem. It's always been enough before. Hoping to get it on the water today and give it a test drive. Figured if new gaskets and fuel tank doesn't help, possibly exhaust issue?!
Thanks for your reply.