Evinrude WOT RPM's are a little high.

sutor623

sutor623

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Hey guys, been enjoying the start of a great boating season. I have a tinytach on my '84 Evinrude 75hp. Prop is a 15P. Had her out last weekend and motor was turning at 5950 RPMs. That was pegged, wide open, after about a minute of getting up to full speed. I had a normal weight on the boat, about what I would expect being on the water. Here is my question. I calculated a prop slip of an amazingly low 6%. The 16' aluminum Starcraft is topping out at 33MPH. Should I go up in pitch to bring rpms down, keep the same prop and set the throttle stop at 5800, or just run it like it is. (Will over revving the engine by 150 RPMs cause me any dismay?) Thanks fellas!
 
BonairII

BonairII

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Re: Evinrude WOT RPM's are a little high.

No problems 150rpm over.

Slap a 17p on her. You'll get your rpm down and your speed up. Do you have manual or power trim?

Check my sig for what I'm running.
 
sutor623

sutor623

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Re: Evinrude WOT RPM's are a little high.

Thanks Bon. You are running basically my same setup. I do have stock power trim. Ill try the 17 once I get some cash :)
 
BonairII

BonairII

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Re: Evinrude WOT RPM's are a little high.

I run my 15p when I'm loaded heavy or want to pull a tube etc. I get about 6100 or so rpm with the 15p @ wot...so I have to back the throttle down a tad.

With some experimentation, you'll find a good trim position to set your motor at. I believe mine was the 2nd hole(from the transom) when I had manual trim.
 
sutor623

sutor623

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Re: Evinrude WOT RPM's are a little high.

Yea when I had my Merc 650 on there the boat liked to porpoise at any position other then pegged in the bottom hole. Man power trim is a blessing!!!
 
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