lower motor mount on 93 120hp

[mouse4x4]

So my lower motor mount has been seperated since I picked this boat up. I have been running it with a hard rubber bungee wrapped around to keep it from kicking up in reverse. I have a new mount is it just going to seperate like the old one is there something I can do to make it a more reliable component. An what am I getting into to change it out.

 

[jerryjerry05]

The job isn't a small one.
If the boats been in salt water one time it can make it a lot harder.
It should last a long time unless you hit something or back into something.
You might be able to do the job with just tilting the motor??
Someone with more experience will know.

 

[Frank Acampora]

Is this engine a Mercury lower unit or is it a Force lower unit? If it is a Mercury, then there are two lower mounts: One on either side of the midleg. Replacement (barring corrosion problems is relatively simple. Remove the cover from each side and the mounts are right there. Remove the bolts and pry out the mount. Drive the front bolt out of the swivel yoke and insert the new mounts.

If it is a Force lower unit it is a little more complicated. Force has two plates with a rubber biscuit glued in between them. To access this you must remove the rear shroud and the front kingpin cover. There is a decent chance that you will snap one of the four bolts holding it. Pry back the engine leg for working room and remove the four bolts holding the mount to the midleg. Again, there is a decent chance that you will snap a bolt or two and need to drill and re-tap it. Once all this is done, the new mount is inserted and all 8 bolts are re-attached. If luck is with you it is about a 1-2 hour job

It is relatively uncommon but certainly not rare for lower motor mounts to break due to rubber/metal glue failure. As long as you don't make it a practice to hit submerged objects at speed. the new one(s) should last a long time.

 

[foodfisher]

I had one (Force) that separated the rubber from the metal. Cleaned the surfaces with alcohol and reattached them with original contact cement. Held for 3 yrs. As far as I know it's still holding.

 

[mouse4x4]

This is a Force design it has the pancaked rubber between two plates I have a new mount as the original is celebrated. What kind of glue did you use on gluing them back together.

 

[Frank Acampora]

I frequently repair these rubber motor mounts. I use an industrial 3M rubber cement. Then, I modify the mount so it will never break again. I also do this with new and good condition mounts to keep them from breaking.

Basically I drill two 1/4 inch holes in the mount all the way through. Then I drill the thick plate to 5/16. I tap the thin plate to 5/16 X 18. I countersink the thick plate about 1/8 deep to allow the two 5/16 screws to move under compression. I then screw in two stainless flat head, 5/16 screws and grind the ends flush with the thin plate. I then peen the ground ends so the screws will not back out.

I can't post photos but if you look up past posts you probably will see some photos and it will be self explanatory.