If the engine is new,after 20 hours it should either improve or deteriorate quickly. I hope it was broken in properly?after 20 hours should be good to go and then some. 275 horses is not really a very high out put.Other than power,what complaints do you have?
I should have reread your first post,,,,what do you expect your boat to do with 170 ish horse power.A lot of boat v-8s run at 70% and its 20 feet long.
re leak down,it would be nicer if all the values were equal.