I have a 22 ft glassstream center console with a 150 mercury 4 stroke on it with a 4 blade stainless revolution prop 17p. It a very heavy prop and it causes some "prop knock" and vibration at idle. if I bump it up a few rpm it is smooths right out. It is a known issue with heavy props and 4 cylinder 4 strokes. I am happy with the performance. Boat tops out at 42 at WOT with RPMs right where they should be. I tried switching out the hub with a flo torq 4 which helped but still there is some knock. I like troll so the knock bothers me more than it would most folks. I was thinking of switching to a lighter weight prop either 3 or 4 blade just to get rid of the knock. Any suggestions for props that would be lighter but similar performance to a revolution 4 17p? Or is is better to just live with it?

lower prop weight aint your problem.
the knock is in your lower unit .
I/e idle loads up , then boat moves then gears slack , then load up.
actually a heavier prop would be better,