1978 Mercury 80hp question

[sparky2k]

I have a 1978 80 horsepower 4 cylinder outboard that I recently purchased. It needed a water pump impeller, I installed a complete pump rebuild kit. Problem now is apparent overcooling????
Block is always cold, water pours out of upper exhaust relief openings.
Does this beast have a thermostat somewhere?
Thanks in advance,
Sparx

 

[emckelvy]

Re: 1978 Mercury 80hp question

No thermostat at all. These blocks do have a tendency to "overcool", since they're 2/3 of an Inline Six with the same cooling system. If idled a lot, this tends to wear out the cylinder bores.

So, it's not the greatest fishing motor, however, for general boating or watersports, she'll run out quite nicely. Just feed 'er good oil and fuel.

Sounds like you've got plenty of water flow, at least you know she won't be going into Meltdown anytime soon!!!

HTH.........ed

 

[sparky2k]

Re: 1978 Mercury 80hp question

No thermostat at all. These blocks do have a tendency to "overcool", since they're 2/3 of an Inline Six with the same cooling system. If idled a lot, this tends to wear out the cylinder bores.

So, it's not the greatest fishing motor, however, for general boating or watersports, she'll run out quite nicely. Just feed 'er good oil and fuel.

Sounds like you've got plenty of water flow, at least you know she won't be going into Meltdown anytime soon!!!

HTH.........ed

Thanks Ed,
Yeah, she is a screamer. Lots of top end, the idle needs help. I suspect the carbs need attention as it had been sitting for a few years.
Tnx again,
Sparx