Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 150hp Merc Mounting Position

Posted by MillRat on 10/21/14 - 6:11 AM
#1

I have a 1984 Outrage 18 that came with a 2010 150hp Mercu Optimax. The first time i used the boat i immediately noticed that water sprays up from the anti-cavitation plate while on plane. I have to trim the motor up considerably to make the spray stop. Currently the motor is mounted in the top hole. I know i need to drop it down. Does anyone have experience with this motor/hull combination and if so, what hole are you mounted in?

Thanks!

Posted by Phil T on 10/21/14 - 7:50 AM
#2

motor is mounted in the top hole


If the bolts are using the top holes, the engine would be mounted as low as possible and need to go UP.

Please clarify.

Without knowing which propeller you are using, the standard recommendation for this hull is 2 or 3 holes up. This means the top set of bolts go into the third or fourth hole, counting down from the top

You may need to go higher, depending on which prop you are using.

Top set of holes

0 <---bolt here is "all the way down"
0 <--- 1 hole up
0 <--- 2 holes up
0 <--- 3 holes up


Posted by MillRat on 10/21/14 - 11:33 AM
#3

Yup, you are right i had that backward! The bolts are currently in the top hole. The prop is a Merc Laser II. Gotta get the lifting eye for the motor so i can make the adjustments and see what hole is best.

Thanks!

Posted by Finnegan on 10/21/14 - 12:50 PM
#4

I have a 1986 Outrage 18 that I bought new, and am familiar with running Laser II props on a Merc 150.

First of all, Whaler's factory engine mounting instructions for the 18 were always one hole up, meaning the second hole down from the top. Any prop could be run in that position. For a Laser II, I would go up one more hole, to the third, or middle set of holes (out of 5). That should give you pretty good all around performance, with zero slippage/ventilation. I would only go up three holes (4th hole out of 5) if top speed is your only objective, and for that you might also consider a Tempest Plus prop, or an Enertia prop. Never install a Mirage Plus on an Outrage 18 - too much prop. The Laser II is a fast top end prop, but is not great at mid range cruising in the large gearcase size. I understand Mercury has just discontinued manufacture of these, which have been in the line for 25 years! In the smaller 4-1/4" gearcase size (75-125HP engines), they are still one of the very best props available for both all around use and top speed.

Even in the two holes up position, I think an Enertia prop is a better all around choice than a Laser II for the Outrage 18 in offshore use. I assume you are running a 19" Laser II with medium vent plugs? That should give you 51 MPH. I also run that prop on the Merc 150 installed on my 1975 Outrage 19

Posted by MillRat on 10/22/14 - 8:59 AM
#5

Finnegan,

Thanks for the info. Hopefully i'll be able to play around with the mounting before i store her for the winter. I'm already getting 50+mph out of her, so it will be interesting to see what happens in the new position.

Thanks!