Wiggly steering Evinrude 20HP 1975

My short shaft 20 tiller steering is "wiggly" .
The whole engine moves quite a bit on the transom mount frame and all I see stopping it is a series of rubbermounts (the parts book calls them), 3 down low and 3 up high.
Probably wouldn't be noticeable on a V hull boat, but on my inflatable it makes it real quirky at high speeds.
I took the 2 "shell" parts off down by the vent plate along the exh hsg, to look at the 1 mount and 2 bumpers in there. They all look like new. I see no way to tighten them.
I was thinking I could make some stiffer ones out of polyurethane but I don't see how those 2 side ones even attach - are they glued? cant be....the parts book shows a gasket? but no bolts or fasteners of any kind - the 2 must screw together I'm thinking....
The 3 mounts up under the pan look "as new" too.
They're all the 1975 original parts, but this motor has real low hours - spent most of it's life in the basement.
Did my mounts go soft? Or is this wiggling normal?
I gotta stiffen it up somehow. It's scary. It feels like your going to get into a speed wobble with the boat.

Re: Wiggly steering Evinrude 20HP 1975

It's supposed to be soft for quiet and vibration-free sake. You have a special situation. Don't know what to tell you except maybe you are on the right track about making some firmer ones. They made harder ones for some high horsepower models.

There is an acorn nut on the lower ones, inside the exhaust housing. Older models had nuts on both ends of the lower ones. Takes different mounts and clamshells to do that. I am parting out an older motor if you want to try that.

Re: Wiggly steering Evinrude 20HP 1975

look up the diagram here may be more detailed. http://www.evinrude.com/en-US/Accessories/Literature/

Re: Wiggly steering Evinrude 20HP 1975

So - nuts will fall into the exhaust housing I suppose if I do try to take those bumpers off? I guess I'll have to drop the lower. I have lots of 90A durometer polyurethane -so I think I will make 2 new bumpers. I found some high perf rubbers for 70HP and such on the web, but nothing that looks like mine