Prop basics??

[AQUAJOE]

I agree with Marine_man. Pitch change with that HP shoulkd be sufficient.

[StCroixNewB]

I'll throw in my two cents and recent experience... I have a 18' deep-v aluminum boat (Monark King 185 - made by Starcraft) and a 140 hp suzuki 4-stroke. It came with a 3blade 14"x17" aluminum prop. At WOT, I was running about 40 mph at over 6500 rpm. This engine would run between 5700 to 6200 rpm WOT. What I read was that for every 1" increase of pitch, the WOT rpm should drop by about 200. I put a 3blade 14"x19" prop on the boat and my max speed increased to nearly 50 mph and my max rpm at WOT decreased to around 5800 rpm. The boat now planes out and rides better and I can squeeze out a bit more speed by slightly over-trimming the engine (pushes mid-50's).

I had called the dealer that sold the boat to me and he confirmed that a 19" pitch prop should have been put on my boat originally so they sold that one to me for under-cost (got a brand-new, Suzuki prop for $115) and I kept my 17" prop that I'll use for pulling skiers (better hole-shot due to faster torque-up when the engine is 'gunned').

Now, I just wish someone would invent a cotter-pin type device that popped-in/popped-out with more ease rather than having to bend the old one out, push it through, bend it back and hope the dang thing doesn't break (I keep a few extras handy in the glove box just in case)...