Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should check?

[Roadblock]

I just bought a old Mirrocraft 15 1/2 Trolling/Ski boat from a family friend. It has a 1974 50 HP Merc on the back. The ID tag is still on the motor, I can post any numbers etc later but the only things I saw on the motor were Mercury, 50HP and Thunderbolt Ignition.

Is there anything I should check over before I take it out? The guy who sold us the boat is a family friend and he said it works fine, he had it out on Lake Michigan last year while his Bay-liner was being serviced. He took himself and two friends out with zero issues. He said he just replaced the impeller last year and it should be good to go.

I don't have money for another motor if I do something wrong and this is my first boat so I really don't know what I'm doing.

I would like to start the motor in my driveway before taking it out to a lake. I bought one of those things you connect with a garden hose, is there anything I need to know about that process?

Just looking for any general advice here! Anything I should check, grease, clean etc?

 

[racerone]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Make sure gearcase is full of oil and no water in it.-----------If carburetors were empty over the " short winter " then you should be good to go.

 

[Roadblock]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Make sure gearcase is full of oil and no water in it.-----------If carburetors were empty over the " short winter " then you should be good to go.

LOL I wouldn't have even known to check for gear case oil.

When you say the carbs are empty, I assume you mean gas? The tank is full so they could have gas in them. Or did you mean water?

What should I do there to check?

 

[SeaKaye12]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Well....a properly winterized engine would have had the fuel tanks either drained (best) or perhaps the fuel was treated with Stabil or equivalent to prevent deterioration during storage.
The engine itself should have had the carbs drained or run dry as the engine was "fogged"....special lubricant inhaled through the carbs at shut-down....and perhaps injected in the cylinders as well.

A properly winterized engine. You could ask if any of those things had been done.

If possible I would start with fresh fuel that you know is properly mixed with quality TWC3 oil.\

Do really do things right the carbs could be cleaned first....but that would involve them being removed from the engine for it to be done properly.

Most likely (especially with fresh fuel) you could start her up and have fun....after checking the lower unit for oil. Carefully check for coolant flow....and just keep a good eye out for leaking fuel anyplace and while you are at it....look over the wiring inside the cowling.

 

[merc850]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Follow this chartView attachment 229346 and I would grease the driveshaft and shift shaft splines which requires dropping the LU.When running with the muffs don't use full tap pressure, just enough to fill engine while running.

 

[Roadblock]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

I would say it was not winterized just base on what I'm seeing. The guy does engine repair etc for a living so I assume if he had problems, he would just fix it as where I wouldn't know how to deal with it not starting.

The tank is over half full too.

I will just dump the gas in my fire pit and start fresh.

I want to thank both of you for the suggestions.

Oh and one last thing. Can someone point me in the direction of the proper way to start this motor?

Looks like the controls have a choke button. An idle start lever and then the main speed control. Oh and key too.

The guy who sold it to me told me to prime the ball until I could start to feel gas filling it but not so much it gets rock hard or I would flood it.

He said to then set the idle lever to about half way and hit the choke button 3~4 time then fire it up. Once it's run for a little bit and warmed up, bring the idle lever back down and engage the actually throttle.

Does this sound about right?

Also is there any advantage to running premium over regular gas? Being its just a boat tank of gas and not an SUV or truck, it wouldn't cost that much more to go premium so I thought I would ask.

 

[merc850]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

You have to hold the choke button down until it starts, the only advantage of premium gas is it probably doesn't contain ethanol.
Just in case you haven't done this take off the cowlings and check the wires for deterioration/corrosion.

 

[racerone]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

No point in hitting the choke button 3 or 4 times as that does absolutely nothing other than make some noise.------Choke button must be pushed while cranking the motor over.----Prime the bulb till it goes firm !

 

[SeaKaye12]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Remove the cowling before you squeeze the primer ball. Look over the fuel lines carefully for cracks and general deterioration. Who knows what condition they may be in.

As you squeeze the ball.....look carefully for leaks! If you see any leak at all....stop and fix what's wrong.

You will know when the carbs are full....the ball will get nice and firm.

Yes on the "fast idle lever".....but NO on pushing the choke multiple times. Just hold the choke "in" while you crank and release it as soon as the engine fires.

You **DO** know that you have to mix oil in with the gas; correct? 50:1 with proper TWC-3 oil. And; you **DO** know that you either have to be at the lake in water....or have proper "muffs" hooked up to provide cooling water; correct?

Just checking LOL!

 

[Roadblock]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

I do understand the mixture of gas and oil.

50:1, and I picked up an EZ-Mix bottle. It is marked on the side for different mixture of gas vs. oil. For example, if you plan to pump 5 gallons you dump the oil into the EZ-Mix bottle on the 50:1 bar to the 5 gallon mark, then pour it into the tank and then pump 5 gallons of gas etc.

I also remember the muffs from when I was like 8 years old. My dad had a pair for his outboards. He would put them over those inlet vents and connect the garden hose for test and tuning in the driveway. I happened to see those in the accessories section of Cabela's when I was buying Marine starting and deep cycle batteries.

Thinking about replacing the line from the tank to the motor, it's weathered. The ball is cracking for sure. Guess I should look under the cover for fuel lines and wiring. Maybe I should pickup new plugs too?

Thanks for all the information guys. I think I'm going to dump the tank of gas tomorrow and get some 93 Premium and try out the motor.

 

[Roadblock]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

Here are some pictures under the hood. Does anyone see anything that concerns them?

20140421_234646_zpsdbfc21a7.jpg Photo by roadblockxl | Photobucket

 

[SeaKaye12]

Re: Just bought my first older boat! Has a 1974 50HP Merc on it, anything I should ch

From the pictures I don't see anything too alarming; at least from a "safety for initial run standpoint." At least one of your fuel lines appears original....the one with those crimped fittings on it. You should replace that at some point.....along with all the other rubber lines. They can be breaking down internally and messing up your fuel.....even if they appear OK on the exterior.

If it were me....I would run it a bit to get a feeling just how much you like it....and to judge it's over-all potential. Then; if you are excited about keeping it....more investment is justified,

So....things you need to watch for are proper fuel mix with no leaks.....proper cooling.....proper lower unit lubrication....and no shorted wires anywhere. Ignition components are expensive and you don't want to risk hooking up a battery if the wires are in bad shape. Very common on older Mercs.