Prop Question 1989 V-4 Evinrude 88 horsepower SPL E88MSLCER

[B.autry4711A]

Hello,<br /><br />I have a prop question. Will going from a 12 3/4" X 21 pitch to a 14 X 19 prop change the RPM's? What I am asking is since the diameter is bigger(14") and the pitch lower(19") do to the surface area of the prop area will my RPM's go up or would they balance out? I am thinking of putting my 12 3/4 X 21 back on to see if the RPM's go up do to the smaller surface area of the smaller prop. This year I just put on a used Tachometer on my boat and with the 14 X 19 prop I got 5000 RPM with me 200LBS, my wife 230LBS, 1 daughet 70 LBS, another daughter 30 lbs, and my daughters friend at 70 LBS and I hauled some food a cooler with beverages and Ice and a full tank of gas 11 Gallons to be exact. The boat is a small fish and ski boat 15.5 footer with an 88 horsepower SPL V-4 outboard. I haven't tested with the original 12 3/4 X 21 prop yet to see what a difference would be. The motor sounds and runs great and the cavitation plate is about 1 inch above the bottom of the keel at the back of the boat. Now when I was running the boat with myself in it I got up to 5200 rpms and trimmed out. I was just wondering what you guys think?

 

[roscoe]

Re: Prop Question 1989 V-4 Evinrude 88 horsepower SPL E88MSLCER

I think you need to get your rpm up a bit further.<br />I'd be looking at a lower pitch prop to accomplish this.<br />Are the props the same brand, model, and design?

 

[B.autry4711A]

Re: Prop Question 1989 V-4 Evinrude 88 horsepower SPL E88MSLCER

Rosco,<br /><br />I believe but not sure that the props are the same design, model, and design. The 14 X 19 I bought off of Ebay the end of last year and used it for the first time last weekend, It is a genuine Johnson/Evinrude prop; However, the 12 3/4 X 21 prop came with the boat when I bought it 2 years ago and I don't know if it is a johnson/evinrude prop but it looks like it is but doesn't say so anywhere on that prop. What prop do you think I should get? I do see one sellin on ebay which is a stainless steel 13 3/8 X 17 prop which is a performance prop. What do you think I should do get that one. In the add the individual describes that it increases holeshot and the speed (by 6 mph) compared to the factory prop he had on his boat. I just want to get your thoughts on this. Thanks