Best way to safely adjust motor height on 115 Merc

[dj01pass]

I have a 115 Merc on a 17Ft Ranger Bass boat w/ a 10 inch set back. It came w/ the recommended 4 blade stainless prop 13 1/4" x 21"P. The problem is that when properly trimmed it only runs @ 4700 RPM with just me in the boat. RPM Range is supposed to be 4700-5400 RPM. I want higher RPMs to account for when I have 2 people on board.The plane on the lower unit is @ equal to or slightly below the lowest point of the hull and @ 14" below the set back. I want to raise the engine one or two holes to get the RPMs up. My old Johnson had slots in the lower bolt holes, but the Merc does not meaning it will not be secure to the transom when I lift the engine. How can I safely support the engine while it is unbolted?

 

[KCLOST]

Re: Best way to safely adjust motor height on 115 Merc

The best thing to use is a hydralic lift and a lifting eye that is esigned for that engine which will screw into the flywheel.

You will need the lifting eye from a merc. dealer. (they are not cheap however, about $80).

There are some other ways I'm sure others will suggest, but a hydralic lift is the safest and easiest...

 

[jtexas]

Re: Best way to safely adjust motor height on 115 Merc

got friends?

Chock trailer wheels securely.
Lower trailer tongue far as it will go.
Construct a sturdy and stable platform for motor.
Station the offensive front line of the Dallas Cowboys strategically around motor.
Remove mounting bolts.
Crank trailer tongue up till holes match.
Replace bolts sealing with 3m 5200.
Don't forget the locktite.

If you don't have any Dallas Cowboys there, you might could fabricate a stand out of 2x4's, galvanized pipe and duct tape.

Sorry about being so flippant...you don't so much have to lift the motor as just keep it from falling over...but on second thought, hoist rental is probably worth the cost.

Especially if somebody in your bass club has the lifting eye - he's not using it right now anyway.

 

[Bob_VT]

Re: Best way to safely adjust motor height on 115 Merc

Jtexas are you sure 5200 is the right sealant? Isn't that a bit too permanent just in-case he has to move it again?

My advice do not use sealant until you are satisfied with the results. Once you are happy each bolt can be removed and re-installed one at a time w/o a hoist.

 

[rivercookdave]

Re: Best way to safely adjust motor height on 115 Merc

hoist is the easiest,if you cant find a lifting eye to borrow,have used a piece of chain and used a couple of the flywheel bolts before,with out a problem,if you have a friend to help balance it,you could use a floor jack.
sounds like you would be better off changing the prop though.

 

[jtexas]

Re: Best way to safely adjust motor height on 115 Merc

I've never had a problem with 5200 being too permanent - given enough effort, it's always come off...haven't tried it, but I believe 4200 is the "less permanent" version. Any case, I would be very reluctant to dunk it without a sealant of some kind.

 

[Chris1956]

Re: Best way to safely adjust motor height on 115 Merc

dj01pass, I drove a 3/8 lag bolt into the header above my garage door. I hook a really wimpy block and tackle to the lag bolt, and use a piece of plumbers strap as the hook on the motor's flywheel. I bolt the plumbers strap across two of the eight bolts which hold the flex plate to the flywheel hub, connect up the B&T and hoist away. Another way is to tie the motor to the header, with the tongue of the trailer down, and lift the tongue, which lifts the motor off the transom.