1991 Gamefisher 15 issues, heavy smoke, exhaust gaskets, lower unit seals

[inlandNWcruiser]

I recently bought a 1991 15hp Gamefisher. As I understand it, this is a Force outboard made by Mercury. I'm not at all a marine mechanic so am looking for some repair advice. So far, I have only done a few minor maintenance repairs - replaced the water pump impeller, thermostat, spark plugs, & broken primer bulb. So far I have only run it at home in a tub of water. The motor starts right up and seems to run well. I am getting lots of cooling water coming out the spray hole.

First - the motor is smoking a lot and smelling strongly of gas. I am still running it on a gas/oil mixture that came with it from the previous owner. So I need to get some fresh gas and oil and give it a try but wondering if there is any specific gas or oil that I should try or other things related to the smoke/gas that I should look into.

Second - I got my hands on a service manual and decided to replace the 2 exhaust cover gaskets as suggested in the manual, but not sure where these are located on the motor, and could use some pointers on how to get to them and replace them.

Third - When I went out to tinker with it today I found a small amout of black oil leaking out of the cooling water intake port. This seemed abnormal to me. Should I be concerned? When I replaced the water pump impeller I also replaced the plastic water line seal that the copper water tube hooks into, but no other seals. The water pump shaft seal looked OK. Do I need to replace it? And there any other seals or gaskets associated with the lower unit? I am planning to replace the lower unit gear oil shortly and will look for any water in the oil.

Thanks in advance.

 

[foodfisher]

Re: 1991 Gamefisher 15 issues, heavy smoke, exhaust gaskets, lower unit seals

Faster responses can be found in the other brands forum

 

[inlandNWcruiser]

Re: 1991 Gamefisher 15 issues, heavy smoke, exhaust gaskets, lower unit seals

Well, here's an update...

I have had it out on the water two times now and it has been running great. It really pushes my 12' aluminum boat through the water nicely. The power head gets pretty hot but I can hold my hand on it for about 3 or 4 seconds so I think it's OK (can anyone confirm?)

Before taking it out, I mixed up some fresh gas and oil at 50:1, along with some Seafoam and Valvtect (ethanol gas treatment) and the smoke problem is better now. It still puts out plenty of smoke when idling in a tub at the house, but I think it's probably a normal amount of smoke for a 2 stroke.

I have not removed the exhaust cover, checked the water passages for obstructions, and replaced the gaskets yet, (as suggested in the service manual), so would still appreciate some pointers on this if anyone has done it before.

The cooling water starts spraying out of the outlet right after I start it up, even when cold. Should the thermostat be holding the water in until it's warmed up? Maybe when I replaced the thermostat I installed in wrong.

I have not found any more oil coming out of the water intake port. Maybe it was just from the grease that I put on the drive shaft seals when I replaced the impeller. After letting the motor sit for several days, I have opened the lower gear oil plug and let a little out. I didn't get any water coming out, but the oil is a little milky looking. It doen't look the same as the fresh oil that I put in there when I changed the oil. So I guess maybe I've got a small leak and need to look into resealing the lower unit.

Any pointers on this motor of mine are greatly appreciated.