Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: evinrude 70 hp propeller
Posted by tdeary on 05/02/11 - 8:34 AM
#1
Purchased a 1984 15' sport with a 1985 70 hp evinrude. I need to know what size prop to purchase for this motor. Thanks.
Posted by Joe Kriz on 06/22/11 - 5:37 PM
#2
Just saw this post and noticed no one responded.
I had the exact same motor on my Montauk 17'.
I used a 15 pitch OMC prop but I also had a 17 pitch that I used once and awhile which also gave me a spare.
Posted by dgoodhue on 06/23/11 - 6:49 AM
#3
Make sure the motor is mounted at the proper height, not all the way down. Good props for your motor would be the old omc 13" x 19P sst mounted 2 holes up or the stiletto 13 1/4" x 17p mounted 3 holes up. Different prop by different manufacturers will have some variation in which pitch works best.
Posted by Tom W Clark on 06/23/11 - 7:05 AM
#4
What propeller you use will depend on what the gear ratio of your motor is and what the WOT range is.
Not all Evinrude/Johnson 70s are the same in this regard and I forget when than model changed.
Posted by Tom W Clark on 06/23/11 - 10:26 AM
#5
Doing some research it appears the 1985 Evinrude 70 had a redline of 5500 RPM and the 2.42:1 gear ratio.
If this is what
tdeary has, he will want a 13-7/8" x 21" BRP Viper, a 13-1/2" x 20" BRP Raker or a 13-1/4" x 19" Stiletto Advantage 4.25.
In 1986 OMC redesigned the 70 with a bigger engine block and a 6000 RPM redline. One would have to drop two inches of pitch for this motor to work on a Sport 15.