1980 75 horse trim/tilt transom mount help!

[bashr52]

I recently sent my valve body off to RRitt to have him go through it, and while I was messing around with the trim system, I notice that my trim cylinder is free to pivot slightly around its mounting bolt. It moves enough that it is no longer contacting the strike point, and has been hitting the very top of it, which bent the metal strike plate, and actually started indenting the lower unit.

Here's a picture of my tilt cylinder, and the damage:

Can someone tell me what I am missing? A picture of a correct setup would be awesome. This is a single tilt ram unit.

Thanks

 

[RRitt]

Re: 1980 75 horse trim/tilt transom mount help!

the transom clamps have to mount on a prefectly flat transom. your transom has a recess in between the clamps. you need to install a plate or something to make it flush.

 

[bashr52]

Re: 1980 75 horse trim/tilt transom mount help!

the transom clamps have to mount on a prefectly flat transom. your transom has a recess in between the clamps. you need to install a plate or something to make it flush.

I guess the picture is deceiving. The transom is flat, but there is an angle iron brace under the transom straps that allows the tilt cylinder to stand off the thickness of the angle iron. I'm assuming that must be another "add-on" by a previous owner? Looks like I have to make some modifications to the system then.

 

[Frank Acampora]

Re: 1980 75 horse trim/tilt transom mount help!



The cylinder must be free to pivot slightly. Remove the angle iron and install an aluminum plate under the whole transom clamp assembly. As RRitt said, the transom must be flat. Fiberglass, especially if the transom os old and possibly a little soft, is just not strong enough to resist the cylinder forces. The back of the cylinder will bear against it and the fiberglass will be indented or worn.

If as I suspect, the angle iron is there to reinforce the transom, replace it with a piece of aluminum angle on the INSIDE, running the full length of the transom. The photos, especially the last one, will give you an idea.

If you do replace the angle iron with aluminum, depending upon your hull, the engine will be raised a bit on the transom. In my case, with the last photo, the engine was raised about 1/2 inch and the hull really did not like that. I could not use any trim without cavitation so I needed to spend a day and cut down the transom that 1/2 inch to put the engine back to correct height. Now, the boat in the center photo has the engine jacked up one inch on the transom and it is very happy. You won't know until you try it.