2020 F4 high altitude operation + break in

[dania02525]

Hello! I purchased a new F4 for my 12ft jon boat, and I'm hoping to get some advice on operating it safely at ~8200 ft. Living at high altitude, I'm familiar with carburetor jetting, and will be trying out smaller main jets one and two steps below my current main size of #60. I also think the motor is lugging, and not reaching its correct RPMs under load. Is there a source for a lower pitch prop for these things? It seems like these are not well supported at high altitude, but I really wanted the wet sump for transporting inside my truck so I went with the yamaha.

Thanks!

[boscoe99]

The Yamaha parts catalog shows a number of propellers with different pitches.