I have a 1976 20 hp that is running at half speed when at full throttle. I recently spun the prop. So while the engine was down awaiting the new prop, I cleaned the carb, new fuel pump kit, and replaced the plugs. Now the engine starts and idles just fine, accelerates just fine, but only runs to about 12 MPH on the gps. The engine does not sound to be reaching the same RPM?s it used to. I did notice my thrust washer did not fit into the prop as snug as with the old prop. Could this be a prop issue? Any thoughts on determining if it is not getting enough fuel, or if it is the prop? I replaced the original prop with a michigan match 032136 and got new prop nuts, but did use the original thrust washer.
