3.7 merc w/alpha drive. Bumped a sandbar last week and subsequently overheated. Replaced water pump housing and impeller, tried to do tune up but junk timing light died on me. Timed it by ear. Took it out on the river today and just started buzzing around. Eventually got up to 175, where I've always seen it run. Stretched out the buzz runto about 5-10 minutes at 3700 rpm and it went to about 190-200 (?)Noticed that when pulling out, under load, I had some pinging. Timing advanced too far?? Will this cause it too heat up as described, or is there blockage somewhere? Bring the rpm's down to 2500 and the temp comes back down, sit at idle and its down to 160-165.
