J
John Squire
Any thoughts on the following problem?My new (to me) 1990 M3-20 (on a Catalina 27) is tough to start (glow plugs always required), runs consistently at 1100-3000 RPM and runs rough, loses RPMs and stalls, (especially after running awhile), at anything lower than about 1000-1100 RPM. Mechanic adjusted idle stop and hauled to check barnacles, no help - I asked about valve adjustment/injector cleaning, but was rebuffed.There's soot on the transom, but doesn't seem to be abnormal exhaust (marina mechanic didn't think exhaust was notably off color either). Fuel has been treated with algae killer and "injector cleaner" stuff.What do I try next?