77 Mercury Trim Locker

douglasjett

Cadet
Joined
Mar 23, 2011
Messages
16
Just bought 77 fiberform with Merc 850 thunderbolt. The motor runs great, low hours, proud to have gotten it for a great price. I finally got it converted to a fishing vessel and noticed that the trim locking mechanism was locked down. I thought the thing was completely manual, spring loaded. Then I read a thread on here from 2001 and you were talking about the thing being hydrolic/electric. So, I don't know where to start. There was talk of chaning the oil (I don't even see a place to do this), and talk of electrical conections? If anyone has the time could you give me a starting point? Does it have to be under power to engage/disengage? Thanks for any help.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,046
Re: 77 Mercury Trim Locker

Does the motor have Power Trim?POWERTRIM&TILT.jpg
If it does there should be 3 trim buttons on the dash or on the control handle, if it doesn't then you should shift the motor into forward (not running) and tilt it up manually.
There are two levers that lock it in the up position at the side of the clamp bracket.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,977
Re: 77 Mercury Trim Locker

Sounds like he has manual tilt. Put the motor in forward and the reverse lock should release. That motor (if manual) is not spring loaded, byt has hydraulic shocks ont he transom bracket. It will be difficult to tilt up, but slow steady pressure will cause it to come up.
 

douglasjett

Cadet
Joined
Mar 23, 2011
Messages
16
Re: 77 Mercury Trim Locker

Yes, it is manual tilt. No it does not have power trim. So, I lifted/started the motor shifted gears in/out/nutral/ect... The lever did not raise, so it is stuck closed. What now?
 

douglasjett

Cadet
Joined
Mar 23, 2011
Messages
16
Re: 77 Mercury Trim Locker

I have posted response on thread, thanks for trying to help me with this frustrating matter.
 

douglasjett

Cadet
Joined
Mar 23, 2011
Messages
16
Re: 77 Mercury Trim Locker

Hmmm, if this becomes a time consuming/expensive problem could I disconect rod and turn it into a manual lock? Only an $800 boat, don't want to spend much.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,977
Re: 77 Mercury Trim Locker

The locking mechanism is a simple spring loaded device. It may be out of adjustment or the release cam may be defective. Remove the stainless steel tilt pin, from the transom bracket. Note what hole it is installed. Now motor should tilt up and you can see the reverse lock hook and the adjustment nut. There is a plastic cam inside the midsection the pushes the lock rod up to release when motor in forward. Try to adjust the lock mechanism.
 

douglasjett

Cadet
Joined
Mar 23, 2011
Messages
16
Re: 77 Mercury Trim Locker

No luck yet, I have raised motor and toyed with adjustment screw. The problem almost seems like the rod is stuck/locked down at the shaft. I will continue to work with. If you have any other ideas I would be greatful.
 

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: 77 Mercury Trim Locker

douglas;

Here is the parts manual for your engine:

http://www.crowleymarine.com/mercury-outboard/475.cfm

In this link you will see item 15, which is the rod end that connects to the reverse hook. The rod 13 passes down through the guide 12.

http://www.crowleymarine.com/mercury-outboard/parts/475_18.cfm

In this one, you will see the cam 46 and underneath that is the cam so you can see the cam edge which the rod 13 rides on. Doubleclick on the picture of the cam to blow it up.

http://www.crowleymarine.com/mercury-outboard/parts/475_21.cfm

http://www.crowleymarine.com/parts/2496.cfm

The cam 46 and the guide 12, you cannot see until you drop the lower unit, which you may have to do as the guide 12 sits just above the cam and it's purpose is to align the rod 13, to accurately line up with the cam. If the guide is missing, which is easy to happen when reinstalling the lower unit, it can cause problems with the rod 13.


Gerry
 
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