Trouble with my 1967 Mercury 650 SL

[Jimmy310]

Hello all,
I have a 1967 Mercury SL on a 16' boat. Long story longer. It sat since 1980.
I got it to run a few times at home. Felt confident to try her out in water.
Got to a lake and it ran OK for about :15, just shut off on me.
Turned on again and ran for another :5, shut off again. This time had smoke coming out when I removed the cover. At the throttle arm, there was some dark grease or heavy oil oozing out. Good thing for my trolling motor. Back at home I put a plastic tote storage box and filled it with water so I did not have to put the water hose and cups on the lower end. It started right up and ran it for :01 at 2500 RPM.
Shut it down and it felt hot to the touch.
Any advise on what could cause such a problem?
More importantly how I can get rid of the problem.

 

[Fuzzytbay]

Re: Trouble with my 1967 Mercury 650 SL

Water pump..... change it, and check the water passages for blockage while your at it. Hopefully, no damage was done, might want to look at the plugs, check to see if there is any metal on the plugs, or if they look like they ran really hot. The gunk, I'd guess is just grease that ran after the motor got very hot.

 

[Jimmy310]

Re: Trouble with my 1967 Mercury 650 SL

I changed out the impeller two weeks ago.
Water was coming out of the holes at the back (top) of the outboard.
By water pump do you mean the whole assembly? IE: Gaskets, Housing, etc?

 

[Fuzzytbay]

Re: Trouble with my 1967 Mercury 650 SL

When you changed the impeller, did you put it in the right way? Also what shape was the old one? Were peice's of it missing? From your other post's, you have bottom end problems anyhow, I'd take it off, and double check it. The overheating issue is common on the inline 6's, if a peice of rubber broke off from the old impeller, it could be clocking some of the water flow. When you say, "by the top", do you mean the top of the motor, or the top of the leg? It should pee out the port side, just below the bottom cowling.

 

[Jimmy310]

Re: Trouble with my 1967 Mercury 650 SL

When you changed the impeller, did you put it in the right way? Also what shape was the old one? Were peice's of it missing? From your other post's, you have bottom end problems anyhow, I'd take it off, and double check it. The overheating issue is common on the inline 6's, if a peice of rubber broke off from the old impeller, it could be clocking some of the water flow. When you say, "by the top", do you mean the top of the motor, or the top of the leg? It should pee out the port side, just below the bottom cowling.

The old impeller was in good shape. No missing chunks or cracks on it.
The motor is a 4 cylinder.
Yes top of the leg, port side just below the bottom cowling is where water was coming out. A little bit but more as the throttle went up.

Do I have to remove the lower unit to check for any clogs?
Where and what do I check?
Where is the thermostat located?
I am waiting for my Seloc manual to come in so I have only parts I see to reference.
Thank you for the reply

 

[moorecomp]

Re: Trouble with my 1967 Mercury 650 SL

You have grease combined with metal dust from the throttle arm. It is on the side cover because it was the only thing holding the lever in place. The lever is coming away from the bearing. The bearing should be almost flush with the outside surface of the arm. A large diameter washer should be under the bolt head to prevent this. Check and make sure the bearing is not frozen and the outer race is not moving in the arm. (Bet it is) Should be a press fit. (Bet it's not)

Craig Moore
Mancelona, MI

 

[Fuzzytbay]

Re: Trouble with my 1967 Mercury 650 SL

When you remove the bottom end, check the copper pick up tube, for clogging. pull it out if you can, sometimes they are stuck pretty good, so don't tug too hard, you don't need any more agrivation. But if it will come out good, if not try blowing air up through it. As for a thermostat, there isn't one.
Double check you put the impeller in correctly, I think the "arms" on the impeller should be bent clockwise. If you changed the impeller, but put it in wrong it would still pump, but not enough water to cool the motor properly.
Those motors should run cool at idle, and when at speed, hot, but not too hot you can't touch the motor on the port side. As for how to get the bottom end set up properly, do a search here on the forum. The problem happens lots, and the fix is much better described by others than I would do.