If the original prop performed ok for you get it repaired or buy an exact replacement. The numbers are on the barrel or hub of the prop. Without a tach reading at wide open throttle we can't tell you what's best. Merc makes a series of four blade pontoon props so check with them but you still need to know current WOT RPM with the current prop to pick the right pitch.
You must run the boat on the water with a normal load and record the highest RPM's. Throttle it up on the muffs and you'll be getting a new engine sooner than you'd like. 5500 RPMs would be the number to shoot for..
So you haven't run the boat yet and have already determined it's under powered! you might be surprised. Pontoons don't go very fast regardless how much power you have. The object is to prop the engine correctly to run at its maximum recommended wide open throttle rpm with an average load. Whatever speed you get is what you get when you have the right prop. Just so you know -- you NEVER - EVER run an engine wide open on muffs. You might be very surprised to learn that you might not be able to shut it off. It's called run-away and it will rev until all of the internal parts try to get out of the engine which obviously makes a big mess. And you can ignore all of the advice here unless you actually have a tach. Without one you don't know how fast the engine is reving.
Best Prop for Mercury 35hp on 20' Pontoon
Linear Mode
