1981 Mercury 115 horse

[schimmi021]

I just bought an older boat with a Merc 115 horse straight 6. The motor has not been run in about a year and I am unable to get it started. There are things I know are working well on the motor which include, the starter (which engages and turns the motor over well) the batter, which i recently replaced, and the plugs (I checked all of them for spark and they all seemed good). The motor seems to want to start when a little gas is squirted into the cylinders but doesnt ever start. It is a little cold out but not too bad, about 60 degrees.

What should I do or check next? I have a feeling it just isn't getting gas. I pump the ball hard but after cranking on it for a while it isn't quite as hard. I am still fairly new to outboards, and have never worked on anything this complex.

Thanks for any input i appreciate it

Lucas

 

[OldMercsRule]

Re: 1981 Mercury 115 horse

I just bought an older boat with a Merc 115 horse straight 6. The motor has not been run in about a year and I am unable to get it started. There are things I know are working well on the motor which include, the starter (which engages and turns the motor over well) the batter, which i recently replaced, and the plugs (I checked all of them for spark and they all seemed good). The motor seems to want to start when a little gas is squirted into the cylinders but doesnt ever start. It is a little cold out but not too bad, about 60 degrees.

What should I do or check next? I have a feeling it just isn't getting gas. I pump the ball hard but after cranking on it for a while it isn't quite as hard. I am still fairly new to outboards, and have never worked on anything this complex.

Thanks for any input i appreciate it

Lucas

That engine has six individual coils fed by two switchboxes n' power comes from two stator windin's under the flywheel.

Verify that all six plugs have lots of fire with a spark tester.

Then, (if hot fire on all six), squirt raw premix directly into all three carbs while crankin' her over.

Make sure the choke werks too when ya push the button on the corntrol, (if not matually choke the ol' girl, [ya have ta pull off the top cover to get at the manual choke]).

Those engines need lots of premix n' choke ta fire up, n' a real hot fully charged battery with at least 750 cold crankin' amps.

If ya have hot fire on all six n' rapid turn from the starter n' fuel n' she still doesn't start; time ta check cornpression.

Hope that helps ya; good luck. JR

 

[Really Old Guy]

Re: 1981 Mercury 115 horse

Lucas, Good time to learn.
Sounds like a fuel problem. It could be a small air leak (your
bulb is not staying up, as you said. I would clean the carbs and
retighten all fuel fittings.

 

[schimmi021]

Re: 1981 Mercury 115 horse

I finally got her started. Full charge battery a little premix in the carbs a hell of a lot of cranking and a little starting fluid. I ran it on muffs for quite a while and all seemed well so i decided to take her out on the river. Got it started at the river and went out slow at first then opened her up alittle and the boat planed right out and really hauled ***. Then after about ten minutes it started to loose speed and the motor would not get back up to speed regardless of power. It would only go to about half speed maybe all the way back to the dock. any suggestions?

 

[OldMercsRule]

Re: 1981 Mercury 115 horse

Sounds like maybe the high speed windings.

That said: I only have one of those six coil types, n' she is now a parts engine.

I only really know the distributor fired girls that I luv. So others with knowledge of these twin switch box stator driven types will need ta help ya with the trouble shoot proceedure.

JR

 

[trendsetter240]

Re: 1981 Mercury 115 horse

Go back to the basics of the fuel system and check there.

Fuel tank: Fresh gas, 50:1 mix, vent open?

The carbs are probably in need of a good cleaning. Get a carb overhaul kit, disassemble, clean and reassemble. Replace the plugs while you're at it.

Basic tune up items first. Also get a compression tester and check compression on all cylinders.

 

[schimmi021]

Re: 1981 Mercury 115 horse

In relation to the fuel fittings ant etc. My gas tank is aluminum or something and the fuel gauge is broken, as in all boats i think, should i replace the thing on the tank and hope it works or is there any other solution to knowing how much gas is in the tank

 

[Lone Duck]

Re: 1981 Mercury 115 horse

Double check tank vent ! Check fuel filters and fuel pump while your waiting for carb kits.