1987 Merc 35hp Outboard....repair or replace?

[Cybersnow]

Bought an 1987 Tracker boat that has a 35hp Merc outboard. First trip out the boat died 2 miles from the dock. It sounded like a fuel problem, but who knows? I looked at replacing the motor but that ran from $5k to $8k. So my question is whether to try and fix it, replace the motor for $5k or just replace the boat for $14k??

 

[SuperD]

You had previously mentioned that this boat meets your needs in a great way for the lakes that you will be fishing. If $14k is your only new boat option it sounds like re-powering would be my choice.

 

[Bduck]

Bought an 1987 Tracker boat that has a 35hp Merc outboard. First trip out the boat died 2 miles from the dock. It sounded like a fuel problem, but who knows?

There is some troubleshooting that can be done before you dig deep into the pockets for a new motor. From the limited dying statement you made 2 miles out it could be a fuel issue. Your on the right track to think this could be issue. Does engine try to turnover when you go to restart it? Have you looked at fuel filters/screens? What condition is the fuel hose in?, could be deteriorated internally clogging filter or cracked allowing air to penetrate. How old is fuel in tank? How long has the boat been sitting since last used? These are just a couple of the least amount expense to repair. Next might be a bad engine mounted fuel pump, you can also do a cylinder compression check to see if you have low compression. I'm seeing a 30+ year old motor that just might need a little maintenance but so many questions need answered first.

 

[Cybersnow]

While the boat is a little ragged and could use some carpet and TLC, it is a fishing boat and seems to be exactly what I need. I haven’t seen a used one around and the pro160 is almost a perfect replacement. But I think I will try to tackle the older motor first. As for Bducks Questions, the answer is all ‘I don’t know”. We put water muffs on the motor and it started up and seemed to run just fine. The fuel tank is an old metal one and the fuel line needs replacement and no clue how old the fuel is. Supposedly it was non-ethanol. I have never messed with outboards before, but will start by replacing the fuel tank, line, fuel, and filter and see what happens. Oh, just found a nice video on maintaining a Merc outboard.

 

[Bduck]

This is a very good history that you know of to get you started. Once you start working on it you'll find that doing the maintenance is not the terrible with 2strokes.

 

[Cybersnow]

One question that I have, resulting from watching the video is;

When you get done fishing and are not planning on going out again for several days, do you start the motor (in the water), disconnect the fuel line and let the engine use up the fuel in the system?

Never did that with my I/Os or my large outboards.

 

[Bduck]

One question that I have, resulting from watching the video is;

When you get done fishing and are not planning on going out again for several days, do you start the motor (in the water), disconnect the fuel line and let the engine use up the fuel in the system?

Never did that with my I/Os or my large outboards.

On my F150 Yamaha its fuel injection, i don't run it dry. My kicker is a 9.9 Yamy carbureted motor, I usually do run it dry so fuel doesn't shellac inside. I never know when my next trip fishing will take place

 

[SuperD]

Does your 2 stroke have an oil reservoir or do you add it directly to the fuel? I was on a boat with a 2 stroke this week that had running problems because of the fuel oil sensor in the reservoir.

 

[Cybersnow]

Got it, will start doing that, though I have been told that running non ethanol fuel will prevent the gumming up of the carburetor.

The previous owner only talked about mixing the gas.

 

[SuperD]

Okay, I recommend starting with the least expensive things first. One of my other buddies that was having running issues was systemically replacing a lot of fuel system components and in the end, it was a spark plug. Start there and work your way up to the rest. Does your primer bulb hold pressure? I, personally, once had on the water dying issues when I had a primer bulb with an air leak. IMO, you shouldn’t have to run a 35 HP dry during fishing season.

 

[Cybersnow]

I did check the plugs, they were dirty but sparking. One of the things I did notice when we were out on the water, trying to figure out what was wrong, was that the fuel line was leaking at the bulb. Also noticed the 6gal can had corrosion and rust on it, my guess is that it is time to replace that also. Just to be sure, I will put new plugs in it along with changing the fuel system up through the filter.

 

[Bduck]

Here is a interesting test done with ethanol gas.

https://www.youtube.com/watch?v=YeCyFxoWPpo

 

[Cybersnow]

It was really interesting. When I lived in CA, the only gas you could get at the pump was ethanol. I had to either go to a hardware sore to buy a quart of non-ethanol or go out of state. One of the many reasons I moved out of CA

 

[SuperDaveMT]

While not related to the dying on the water issue, I would also replace the water pump impeller if it hasn't been done recently or you aren't sure when it was last done. Kits are relatively inexpensive and it's not too difficult of a DIY project - lots of Youtube videos out there. Don't forget about your trailer bearing also - might be due for a repack.

 

[Cybersnow]

thanks, will take a good look for a water pump impeller kit. Also one of the first things will be a good lube on the trailer and maybe some new tires. Nothing worse than a flat on the way to the lake first thing in the morning. Also will get a couple of lug nut locks as I had someone try to steal my wheels once.