1977 Mercury 850 serial # 4721552

ddtacm

Cadet
Joined
Oct 18, 2012
Messages
22
Hello All,

I am new to this forum, living in lower Alabama near the coast I recently purchased a used boat and motor my 4th boat
in 25 years. It is a 1977 bass boat with a 1977 Mercury 850. My quesion is can anyone tell me about the thermostat on this motor. All parts breakdown and manuals do not show a thermostat for this motor. I want to make sure all is good before I take her out. New water pump, spark plugs, timing,fuel lines, tank cleaned, wiring, ext. 140 PSI on all 4 cylinders. I am concerned that there may be a hidden thermostat in this motor. Or , how is the temp. controlled? is just flow or is somthing hidden in the motor I have missed? Thanks in advanced Guy's......
 

ajgraz

Lieutenant Commander
Joined
Mar 1, 2010
Messages
1,858
Re: 1977 Mercury 850 serial # 4721552

No thermostat or poppets on that motor. Mercury did not use those on many of their outboard models in the 70's and 80's.
 

ddtacm

Cadet
Joined
Oct 18, 2012
Messages
22
Re: 1977 Mercury 850 serial # 4721552

Thank You Sir... I went over the engine with a fine tooth comb. I really thought I had somehow overlooked the thermostat hidden somewhere in my motor. Now I can continue with the restoration. I will submit some pics. when she is seaworthy.:)
 
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