1978 115 hp Mercury, need help!

[deerslayer1]

Ive got 1978 115 hp Mercury that I am trying to get going again. Last time it was ran was 22 years ago, and nothing was wrong with it at the time. Would it need new pistons? It is a little muddy here so I havent got the chance to get it out in the open yet. I was just thinking about honing the cylinders if they are rusty and putting new rings in, and rebuilding the carbs. I want it to be dependable, there are not many hours on this motor. Lower unit is good. Thanks
Kenny

 

[Barnacle_Bill]

Re: 1978 115 hp Mercury, need help!

http://forums.iboats.com/showthread.php?t=158086

 

[tashasdaddy]

Re: 1978 115 hp Mercury, need help!

it may not need anything, it was only used 8 years. impeller, carb cleaning and rebuild kits. i would tilt it as high as you can get it. remove plug, put some marvel mystery oil in the cylinders, let it sit in there a day or 2. then lower motor catching excess oil, now put a towel of the the head end, to catch any more oil. now turn the motor over by hand, feeling for any hard spots. then follow this. http://forums.iboats.com/showthread.php?t=158086

 

[deerslayer1]

Re: 1978 115 hp Mercury, need help!

Thanks guys, I will hopefully go cut the trees down around the boat tomorrow and pull it out of there, and take a look at the engine. Asof right now im hoping a simple carb cleaning, new water pump, plug wires and spark plugs will do the trick.

 

[Clams Canino]

Re: 1978 115 hp Mercury, need help!

Probably will. Change the lower unit fluid also.

-W

 

[deerslayer1]

Re: 1978 115 hp Mercury, need help!

Ok ill do that too, but as mentioned above, he said that I need a new impeller. could I just get away with that or just get a totally new water pump?

 

[Chris1956]

Re: 1978 115 hp Mercury, need help!

You should replace the impeller, ss plate and the gaskets. That should do it. Inspect the pump housing and base seals. If they are OK, you should be fine. After you get it to run check the gearcase for water intrusion (milky oil)

 

[8075mercury]

Re: 1978 115 hp Mercury, need help!

I would check the wiring real closely as during this period, Mercury used (I think) aluminum wiring which is notorious for insulation deterioration and breaking.

 

[Chris1956]

Re: 1978 115 hp Mercury, need help!

Actually the wiring was good marine rated copper. It was tinned, so it looks like aluminum. However the point is correct, at it's age the insulation falls off and you get shorts. The good news is that the motor wiring harnesses are available aftermarket.

BTW - My '93 Merc uses a non-marine wiring harness. I do not expect it will last 30 years.

 

[jimg984]

Re: 1978 115 hp Mercury, need help!

also watch out for a small hose that feeds excessive oil/fuel from the lower bearing to the top bearing....... these are bad to rot under that black engine cover

 

[deerslayer1]

Re: 1978 115 hp Mercury, need help!

Got it all taken apart, gearcase oil was a dark red, and no milkyness. wiring is really bad, i have to replace just about every wire in the motor. It does turn over, there was no rust in any of the cylinders. Does anyone know what this motor would be worth if I got it going?

 

[Chris1956]

Re: 1978 115 hp Mercury, need help!

Certainly the value of the motor is market driven. Most shops won't work on them, so the buyer will need to do his own work. If you can get $300-400 for it, you should take it.

You can part it out for more.

 

[jmills1978]

Re: 1978 115 hp Mercury, need help!

i am looking for a lower unit for that 115.do you want to part it out?and how does the dist look(the wires coming out of it?

 

[fourpucks]

Re: 1978 115 hp Mercury, need help!

i am looking for a lower unit for that 115.do you want to part it out?and how does the dist look(the wires coming out of it?

i have a 115 mercury for sale--are you interested??