Re: 1972 Johnson 2hp – low speed and idle problem

[Don]

Stan, you mention that the engine doesn’t look to have a lot of time on it, and no signs of overheating. But, someone may have run it without enough oil and scuffed the pistons/scored the walls. Again, please don’t rip the engine apart based on my evaluation of your compression readings, many gages give inaccurate readings on engines like this with small combustion chambers.
The easiest test at this point would be to just try another carb, but I’m sure you don’t have one handy. You mention having another look at the throttle plate, so I will assume it hasn’t been messed with, isn’t sticking, and closes all the way at idle. Did you try feathering the choke on and off at lower speeds to see if that helped keep the engine running like Pappy suggested?
Are you sure the engine isn’t losing spark at low speed?
In any event, I guess it isn’t a big deal to pull the head and exhaust cover on this engine, provided it hasn’t been used in salt water.