Mariner 50 HP overheat alarm

McGurk · #1 July 30th, 2002, 12:49 PM

My 1986 Mariner 50 sounds the temp alarm only at WOT. Replaced the water pump and have good telltale water flow before and after the replacement. Temp sensor seems OK based on a stove top test. Does anyone know if this engine has a thermostat? The manual is not clear about this. It is a 3 cylinder 50 HP model.

orca · #2 July 31st, 2002, 02:50 AM

G'Day Merc were going through a transition stage with their 50hp at that time, your motor could be one of 2, the older motor had a clam shell cowl and MAY have a thermostat, the only way to tell would be to remove the exhust cover plate. the later motor had a lift off cowl, this definatly had a thermost mounted at the top of the exhust plate and easily accessible.

McGurk · #3 July 31st, 2002, 09:09 AM

The motor has the clam shell cowl which would make it the older model you described. If it has a thermostat, please tell me were it is and how I get to it. No information about it in the Mariner manual. I am very good with most mechnical things but this is my first outboard engine. I wish it was a diesel, I would know what to do.