Mercury Classic Fifty Reports

[lureman]

My son is looking at buying his first boat/motor. We came across a Lund S 18-20 1981 boat which is in great condition, our question is on the motor. The boat has a Mercury Classic Fifty 45 horsepower outboard which is a 4 cylinder, I believe 1987. The motor is oil injected and has a seperate storage unit for oil which is mounted to the boat floor. Does anyone know of the realability of this motor and the oil injection system? Will this motor troll down? Any comments appreciated.

[92python]

We had an 81 4 cyl 50 Merc for about 17 years. It was a very good motor that trolled down very well. Never had a problem with it. It wasn't oil injected though.

It did burn through a 6 gallon tanks fairly quickly.

[tackltime]

I have a 1987 merc classic 50 4 cyl.i removed oil pump system on advice from longtime merc mechanic and run 2 6gal.cans.i mix right in those cans.irun this on a 16 ft alumacraft.i normally troll crankswhen fighting a wind with this.trolls great.also get good gas mileage.seems a bit underpowered butif i ran a couple degrees less pitch on prop it would be fine.good motor real smooth.hope this helps. tackltime

[New Yankee]

I've got an '81 50 as well and it's a dandy. I understand the earlier oil injectors had issues and most folks did as mentioned above - plugged them off and ran mixed.

[iffwalleyes]

I have a "89 45HP Classic Fifty mine doesn't have oil injection on it maybe it was removed but I know it doesn't have one on it right now. Anyhow it runs great and it trolls down really nice for me. I had problems with getting mine dial in so that it would troll down but now that it is it runs real nice.

[fishlakeman]

I have a 1986 merc classic 50 and that motor has been bullet proof. My grandpa is the original owner and the motor has been on a 16 Lund Predator. We haven't done anything to that motor except put stable in the gas tank and drain and replace the lower unit oil yearly. The oil injection floor unit has worked great. The low oil alarm even still works, as it went off on me last year. I'm guessing we only put about 25 hrs on it a year, but it still trolls at low rpm's with the occational sputter. All we do is backtroll and it is usually as low as the throttle goes and it trolls excellent. Hope this helps!

[lureman]

Thanks for the info. We purchased the boat today, brought it home, put in fresh gas and had it running in no time. I'm going look for the alarm nice option to have. Haven't decide if we will swich over or stay with injection.

When washing up the boat found a terrible smell, took off the seat to find a family of mice had made a home in the foam floatation, holy cow for a mess! Pulled off the other two seats to find similiar troubles. When all of a sudden a mouse comes flying out of the hole, lets just say the crew was jumpin ship aweful fast! Will have to replace foam, planning on using some roofing foam. Anyone know of troubles if we go with the roofing foam?

Thanks for the help!

[mechanictim]

Just as a little insurance it is a good idea to premix the oil and gas for the first tank of the season. Fill the oil reservoir to the top. After running a half tank or so you should see a drop in the oil level. That will tell you the oil injection system is working. Then you can run straight gas in the tank and just add oil to the reservoir. At the end of the season premix the oil and gas again and add some stabil or seafoam to the tank for the last tank you use before storing the boat. The oil in the gas helps keep the fuel pump working and the stabil or seafoam keeps the fuel from gumming the carb.

To replace the foam there are some very good pourable two part polyurethane foams available. A good marine dealer should have some or they can be found online.