Overheating 70 hp outboards

[Claude Moreau]

I recently had two 1987 Mercury 70 HP outboard installed on my boat. My mechanic installed new thermotstats, but removed them because the alarms go off while running with the rinsing earmuff on. The alarms also go off while running a few minutes at highest rpms on the water. One alarm still goes off while rinsing, even without the thermostat. What could be causing the overheating and how can it be fixed? Any suggestion would be appreciated.

 

[mellowyellow]

Re: Overheating 70 hp outboards

have the impellers been replaced?

 

[Elmer Fudge]

Re: Overheating 70 hp outboards

If you run in saltwater, check the poppet valve,since changing the t/stat was necessary.