Merc 650 65hp...1975? Thermostat issue??

[Mainiac]

Hello All,
I recently bought a boat with a Mercury 650 65hp outboard....i believe its a 1975, one of the carbs was gummy, so I cleaned it and got it fired up. It was pumping water great, then stopped. I used a compressor to blow through the tell tale and have water flowing once again. I have not had it in the water yet, I have been using muffs in my dooryard. When the motor is running sometimes it will puff steam/water out of a hole on the side of the motor, doesn't seem normal to me (first time really working on outboards). any input would be very much appreciated.

 

[Mainiac]

Re: Merc 650 65hp...1975? Thermostat issue??

Is this the poppet valve or thermostat? is something stuck causing water/steam to come out of the hole?

 

[Mainiac]

Re: Merc 650 65hp...1975? Thermostat issue??

Called a dealer that had serviced this engine for the previous owner.... he said it was normal for that model to do that but he had never seen any other model that does this.... anyone know it theres any truth to that?

 

[Moody Blue]

Re: Merc 650 65hp...1975? Thermostat issue??

I don't believe that motor has a thermostat.

You should be getting a steady stream of WATER from the telltale. Steam is definitely bad. I'm assuming you are talking about the telltale outlet?

If you don't know the history of the motor, it would be advisable to replace the waterpump impeller and possibly the whole pump assy.

 

[Mainiac]

Re: Merc 650 65hp...1975? Thermostat issue??

the hole i was talking about is not the tell tale...... it is on the side of the engine a small pin hole in the cast aluminum cover, if this motor has no thermostat then it is where the thermostat would be.... not the tell tale

 

[toddy2pints]

Re: Merc 650 65hp...1975? Thermostat issue??

scrap the muffs,try running with the leg in a tub! just a thought.

 

[latin monkey]

Re: Merc 650 65hp...1975? Thermostat issue??

is that small hole in the exhaust cover?

 

[Faztbullet]

Re: Merc 650 65hp...1975? Thermostat issue??

Thats the "poppet" valve.....

 

[Moody Blue]

Re: Merc 650 65hp...1975? Thermostat issue??

the hole i was talking about is not the tell tale...... it is on the side of the engine a small pin hole in the cast aluminum cover, if this motor has no thermostat then it is where the thermostat would be.... not the tell tale

Can you post a picture ?