Going from a round ear prop to cleaver

[biggdave92]

Here are my numbers:

1.85 ratio
6250 RPM's Tiny Tach
36 mph GPS
10 1/8 x 12p Prop

[JohnsonM50]

Here are my numbers:

1.85 ratio
6250 RPM's Tiny Tach
36 mph GPS
10 1/8 x 12p Prop

That works out to be a potential speed of 38.4 mph making your efficiency well into the 90 percentage. Thats VERY good as is. Next figure what your motors safe hi-est RPM is & where the most torque is. You might not want to increase pitch, Ive seen it enough that less is sometimes more & what seems should be is often nearly opposite. Unless your boat accelerates REAL hard more might slow it down. Since your present prop is doing what its supposed to & you want to go faster you need to look at the whole thing.. Weight & distribution, motor set up. When/if you do change something take notes. Try not to do too many things at once so if something does help you know what change it was.

[Ted March]

Maximum Potential MPH (No Slip )

MPH = RPM X PITCH X GEAR RATIO / 1056

Gear Ratio = 1.85 / 1 = 1/1.85 = .5405

MPH = RPM X PITCH X G. RATIO divided by 1056

38.388 MPH = 6250 X 12 X .5405 divided by 1056

GPS = 36MPH

Slip = 2.388 MPH

Slip = 6.22%

[trentbmx95]

I have a 1996 Evinrude 88 SPL 2 stroke V4, and im wondering if replacing the stock REB prop with a cleaver racing prop would harm it or mess with the exhaust or have any cons with it. It is a 13 spline and im looking for a 26 - 28 pitch 13" - 14" in diameter racing cleaver prop. From my amiture thinking i would think replacing the REB prop with a cleaver wouldnt have any cons EXCEPT maybe how the water flows to the prop. Would the exhaust get in the way making the prop catch the exhaust fuems wich would make it not perform its fullest performance? I dont know im leaving it up to you guys, please help me!!