Mid section motor mounts boken???

[manitouwadgeman]

I am running a 1978 50 hp mercury o/b.
Serial #5111311 1978-M-50A
Hit a rock going full out. Motor still ran fine (vibration tho becasue of blades broken).Replaced the prop. Scag is now gone too.
Noticed the 2 top "mounting bolts" going into the midsection from the transom mount, now allow the motor to move about 1" (front to back).
I can't see any broken metal and it looks like the two bolts had rubber gussets around them. Did the rubber gussets get knocked inside when the motor slammed upwards? Can't find any diagrams in my manuals about the two bolts and how to repair the area. Can't figure out how to even get into the housing to see what happened. Any body with info PLEASE HELP.

 

[Chris1956]

Re: Mid section motor mounts boken???

Most Mercs have rubber and steel motor mounts captive in the exhaust extension to Midsection joint. These are joined by bolts to the steering arm. They do go bad after a while. You might see if you can obtain new one and install them. You will need to remove the gearcase, powerhead and a bolt or two on the exhaust extension. The mounting bolts are likely Grade 8 bolts, so replace with the same kind.

If you look under the lower mount covers, you can see the motor mounts.

 

[manitouwadgeman]

Re: Mid section motor mounts boken???

Thanks for the input. But the bolts appear fine. no rust. still attached to
steering arm. Where they go into the exhuast/midsection, the holes they enter are clean, no broken metal etc, but they don't seem to be attached to anything inside anymore. How and what do they attach to inside the housing?
Do they bolt to the housing inside to a plate or something or did large rubber grommets hold them in place, in the holes they go though?
Tle lower bolts seem to have a rubber grommet bushing going thru the housing. Are the top ones the same?
If I take it all apart , can I just push the rubber grommet bushings back into the housing? Or is it more involved?

 

[Chris1956]

Re: Mid section motor mounts boken???

The upper rubber mounts are a steel tube that just fits the bolts(say 7/16" ID), inside a larger steel tube (say 1-1/4" ID) that fits the casting in the exhaust housing. The two steel tubes have rubber between them, very much like a prop hub and blades are connected by rubber. I will guess that on your motor the rubber connection has failed.