Isn't the sprocket on the. rear the same as on the 2 cycle. it sounds like a typical 9 hole one. If it is you can probably get the missing piece from one of the 2cycle sellers. If worse comes to worse use three finder washers and grind them to fit against each other maybe. The sprocket itself should hold it mostly flat and will be stiff enough to hold the washers. I had planned to do that for an electric engine I considered mounting.

I'm sure someone can make you an engine mount that will work. It looks like it might be a flat bar with a pole clamp on each end. Lots of guys here have welders. In the words of Jimmy Valvanno never give up, never give up, never give up. Mechanical things often humiliate me but I seldom let them beat me. Oh course I usually have to get someone to explain them to me. Hang in there you can do this.

Ps sometimes you just bite the bullet and give the guy the negative. I have done it twice and to heck with them. Both times we worked out the problem and withdrew it.

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