What size prop?

[spareparts]

my "81 has a 21 pitch on a 200, i don't know how it will run since i haven't had it in the water yet, but that prop looks like it has been on there for a while. The 15 sounds a little steep, i'd try a 17. Just prop it out so the engine will turn the high end of the manufactures recomended rpm range with a light load, trimmed out. Hook a shop tach up to check your tach before you start changing wheels, its suprising how many tachs are off.