Here we go again! We turned the flywheel just enough to free up the spark advance and tighted it back down . Than we did a compression check and one cylinder was low. So we put in a new head gasket(old one was shot) and the compression came back up to match the other 3 cyl at 100#(Yea! so happy it wasn't piston ring problem causing it, Yea!). Took her to water and she started fine. Put her in gear and she shut down immediately plus we noticed turning the steering wheel was much more difficult (because of fulling with flywheel? maybe liquid wrench dried out steering assembly?) So after several tries she started and after about 300 yards she shut down from over-heating.AGAIN! We just put a new water-pump/impellar two weeks ago. Now hubby did start her quickly a few ok, several quick times without the hose connected. Dropped the gearcase again and new impellar was melted down AARHHH!! Did we learn an unfortunate lesson here(never start without water)? Called the parts guy up to see about another water-pump kit and he says it may be therm problem. Took apart therm cover to find nothing there. No therm. Our Clymer doesn't show specs for this 1977 Johnson as far as therm removal/replacement. Could it be it never had one?? I think this engine was made only that year. Also, we did another compression check while the gearcase is off and all cylinders dropped to 60#. Is this normal without the gearcase attached? Help! Again! Thank you guys.