hello again, i have a steve muck circus circus fiberglass scale hydro. its powered by an old ops .65. my question is what is a good prop to start out with? the boat never really comes on pipe (mac tunepipe). i was told to run the motor rich (sounds like a 4 stroke). i also run 20% nitro. do marine engines require higher nitro? how do you really tune these inboards when there is no load on the motor? also should the carb be open just alittle when you launch or open a little more for higher revs? please give me advice. thank you in advance.