So I have a 24' Hewes with twin f-100's. the boat currently has Solas 13-1/4 x 19 stainless 3 blade props on it. Not quite getting max rpm's out of motors, about 5200-5400 with full fuel and light load (although this early Hewes carries 160 gals).
boat has sit for 2 years so it does have old gas in it, I dumped a bunch of sea foam in it and replaced timing belts (1300 hrs on motors).
I'm going to "shock" treat the motors with an additive that yamaha sells to remove built up carbon & stuff, then change oil, plugs, filters. All that might improve performance but since I'm going to run the boat as a water taxi, I need to be hauling 7 people & gear.
also will need to run alum props; I have a set of 3 blade alum 12-5/8 x 21 but won't that pitch decrease hole shot? Also have one 13 x 19 alum prop and one 13-5/8 x 13 prop, not sure how the previous owner ended up with un-matched sets.
what do you guys think would be a better match for what I need to do? Max top end is not too important but since I'm not dealing with gobs of torque with the 100's, trying to keep the power band optimal.