1993 Evinrude 15 HP prop was a 9.5 x 12.5

[harleysr1]

Bought a 14' Sea nymph with a 1993 Evinrude 15 HP 2 stroke outboard. When I took it out it would not plane out. the RPM's wouldnt but about 1/ of the RPM's that the motor would produce why running sitting in neutral. The prop was a 9.5 x 12.5 and dinged up pretty good. I took my Dad's 15HP Johnson prop (9 x 11) and it worked super, boat planed out etc etc, no vibrations at all. now my question is what is the best prop for my boat/motor combo. I have a FM146 sea Nymph 14' long 68" beam 90 payload/motor etc.

thanks

joe

 

[jestor68]

Re: 1993 Evinrude 15 HP prop was a 9.5 x 12.5

I see 4 different 9-1/4 X 11 pitch props in the handy dandy iboats prop section for your motor. Since your dad's 9X11 worked good, one of these should fill the bill. The quarter inch difference in diameter won't make any difference.

It would be really cool if you could hook a "Tiny Tach" to the motor to confirm the WOT rpm. That way you would be absolutely certain you get the right prop. Test with your dad's 9X11 to make sure you're getting 4500-5500 rpm at full throttle. It could be you need to go even lower than 11 pitch. The only way to know is with a tachometer. You cannot tell by listening to the motor. They sound like they're screaming at 4000 rpm, when they need to turn up to at least 5000 rpm.

 

[steelespike]

Re: 1993 Evinrude 15 HP prop was a 9.5 x 12.5

My info indicates that the 15 is rated at 5500 to 7000 beginning in 89.
Motor is intended to push boats like yours so your 12.5 is intended for lighter faster boats.
Not even listed here at boats. As Suggested your fathers 11" is a good starting point.
A tach and gps could really get you setup.

 

[harleysr1]

Re: 1993 Evinrude 15 HP prop was a 9.5 x 12.5

well I bought one already. I bought a 9" x 10". I know how it runs with a 11" pitch so I figured I would buy a 10" and if it is better then ok, (maybe go to a 9" pitch) If it is worst get a 11" sell my new 10" here or on Ebay to re-coop some money. I heard props are boat/motor specific but was trying to compare. I am not going to mess with it too much more as I am hoping to get a 25-35 hp motor here in the near furture.

 

[steelespike]

Re: 1993 Evinrude 15 HP prop was a 9.5 x 12.5

What ever you end up with It needs to be propped right for performance,economy and the health of the motor.