Trojan Boat Forum

before u get into the props i would fix the trim tabs...ps by having the trims tabs down after planing off pushes the bow into the water and she starts to 'plow'.....please note that i dont kno ur boat but that is usually a characteristic of full trim down......by having her plowing creates a load...ur WOT rpm figure will change with load ie how much fuel on board,,how much gear stowed..tuna towers..crap on bottom...chipped and pealling bottom..trim tab position....how many people on board

Props are the very last thing I would consider. You are right it should turn near 4000 at WOT. Fix the trim tabs, they make a world difference. Are you running old fuel, do the 4bbls open all the way, is your timing advancing, is your tach correct, how clean is the bottom, fuel filters/water seperator clean, gas tank vents open... lots of things to consider before props. Has it ever turned more RPM's - if so, its not the props.

I agree with all the above... and would not expect a 13x11 to be over propped for your boat....

One other thing to check: is your throttle cable opening the carbs all the way.

id check whatever doesnt cost money first....like carb openingthottle plate and choke opened...spark arrestor...timing/advance....check gauge by borrowing someones timing light that has rpms on it....is the bottom clean? ....

My 1972 F30 has twin FI merc 350's at 330hp ea, turning 15X17 wheels. WOT is about 4400rpm (rev limiter) at 33 knots GPS. 17-18 knots at 3200rpm and 8 knots at 1800rpm.......John

330hp out of 350 nice