1994 Mercury made force/gamefisher 15HP. Merc model 58150, Sears 225.581506. Came as freebie w/Carolina Skiff I bought end of June. Power head was semi-seized with fried bearings. Put on new short block, replaced channeled head, and all new gaskets. New thermostat, water pump rebuild fit, re-built carb. Tested in trash can. Ran OK. Teletale water pumped out of both holes.<br /><br />Took out for boat-ride, slow speed, 25:1 break-in mix. Thought the little bit of smoke coming off the head was the just the new paint cooking....Wrong!<br /><br />Motor stopped-flywheel seized. Restarted OK 30 minutes later. Took off and inspected head- OK inside. Re-torqued exhaust port. Re-started OK. <br />Took out thermostat and got a ton of water up my nose it was pumping so well.<br /><br />Ran cool as a cuke without thermostat in place. The rubber channeling gizmo that the thermostat sits in makes no sense as I can't figure out where the hot water vents when the thermostat opens.<br /><br />Any problem running without the thermostat during the hot summer months? I was planning to put a nylon bushing in where the thermostat sits to simulate the backpressure that the thermostat would create if it were installed and have the hot water vent off the back of the motor leg.<br /><br />Any chance I screwed up when I reset the short block onto the motor leg. I hope that gasket that sit between the leg and the block didn't have a wrong side/right side......??????
