The condensers will go bad before the coils. The Johnson coils are pretty good.
There is a small cover on the back of the exhaust housing, unless you have the cutout lever, the cover is held on with two bolts. Take it off to open the exhaust. See if it runs any better, if so then the clogged leg could be the problem.

If your testing it in a test tank these motors don’t pump water well or at all unless on a boat. You probably already know but it has no pump, the prop and some forward motion is necessary to get it flowing.