Re: what year and hp clinton?
You might try discount marine parts.You might find the diaphram at a small engine shop.It may use a Chrysler connector.
In my opinion the motors were marginal when new.Noisy,vibrate,finicky
unerpowered.If it was mine I would part it out and put the money toward an Evinrude/Johnson 5,5.5,6,7.5 or 8 hp from the early 50s to the 80s.