Prop Principles

[99yam40]

what changed your mind from the 12 pitch Ken recommended?

[Zara Spook]

what changed your mind from the 12 pitch Ken recommended?

PowerTech recommended a different model with 11", and Ken thinks those guys are usually on-target.

[robert graham]

Google: Michigan Wheel Propellers for reams of information regarding all details about props....they sorta wrote the book on the subject. I'd be the first to admit that I'd don't know beans about the technical aspects....all I really know is that my C90 Yamaha has a Ballistic/Michigan Wheel stainless steel prop 13-1/2 X17 and it gives me about 5500 RPM's wide open fully loaded and trimmed up....if I had to change my boat or motor I'd need some help with choosing the ideal prop...Good Luck!

[zenoahphobic]

That 12 is putting your boat in the slow category.
It gets annoying when pitch is not the pitch ( the only standard we go on to ball park guess).

[Zara Spook]

That 12 is putting your boat in the slow category.
It gets annoying when pitch is not the pitch ( the only standard we go on to ball park guess).

I think it's in that category whether I like it or not. The Yamaha Performance Bulletin got 6050 RPM at WOT with a 12" pitch, and that was at only 34.5 MPH. Right now my 15" gets me in the same ballpark speed-wise, but the motor lugs and the holeshot is pathetic.

The idea is to get the top speed possible at the max RPM, while improving the holeshot a great deal and putting an end to the lugging.

[Zara Spook]

Part of the issue is that Carolina Skiff specifies that a 60 HP is the max for the hull, when it should really be 75. The hull weighs nearly a thousand pounds dry. There is no reason that should be maxed out at 60.

[Zara Spook]

I think it's in that category whether I like it or not. The Yamaha Performance Bulletin got 6050 RPM at WOT with a 12" pitch, and that was at only 34.5 MPH.

The good news, however, is that it also got nearly 9 miles a gallon at nearly 30 miles an hour. That's unheard of fuel economy at a fairly good cruising speed.

[Zara Spook]

Just an update on this. I took the PowerTech SRD3 11" pitch into flat and calm conditions this morning, and the holeshot was much improved, while RPM at WOT were 6000-6100. MPH (GPS) at WOT and optimal trim position was 32-33. MPH at 5500 RPM was 30.5.

I have smart tabs and had them on position #2, which is almost the most aggressive position in terms of sternlift, but probably also the most "aggressive" position in terms of drag. I'm thinking I might get better top end by tinkering there.