1983 80hp Merc. Will not restart easily after warmed up?

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packer_fan_46

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My 80hp Merc will start and idlle, it will go to WOT without problem and stay there, however, when I shut the engine off to retreive a skier, the motor will not restart. It will turn over, and almost start, and then will stop. I repeat this numerous times, each time it almost starts, then quits. Eventually, the motor will restart.

I just purchased the boat this summer, and the previous owner burned alcohol gas in it, which is a no no for this vintage of motor. I am thinking it is a fuel pump issue, maybe a kit is needed? Thanks. The motor is on a 1984 Sea Nymph Fish and Ski, nice boat.
 
countryboy26047

countryboy26047

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

Have you ever checked your primer bulb after shut-down to see if it's still tight? I have a '75 merc 85hp and was having the same issue with it.. I de-carbed the motor with sea-foam, which helped a little, but then I found out that my primer bulb was actually bad, and was once the motor shut off and the pump stopped sucking fuel, the bulb wouldn't hold the prime. Replaced the bulb, and haven't had an issue since. I can shut her down for hours at a time now and restart with just a small amount of choke.
 
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mr 88

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

With a bad one way check valve in the primer what happens is when you shut down the fuel is siphoned back into the gas tank and it pulls fuel from the carbs as well.The best way to start it when cold is to pump it a few extra times than you would normally do.
 
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packer_fan_46

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

mr 88 said:
With a bad one way check valve in the primer what happens is when you shut down the fuel is siphoned back into the gas tank and it pulls fuel from the carbs as well.The best way to start it when cold is to pump it a few extra times than you would normally do.
Click to expand...

Thanks for the info. I looked at the primer bulb and fuel line and I found that I have an Attwood bulb, line, and plastic fittings. The fitting that twist N locks into the fuel tank will spin on the fuel line, I do not think this is normal. It turns with the fuel line clamp in place, which is an air leak. So I went to the marina and purchased a Merc fuel line and aluminum fittings, the whole assembly costs just shy of $100.00 (ouch), but I am sure it was made with these fittings in mind.

I will give it try and see what happens. Thanks for both of your help.
 
backlashed

backlashed

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

I have the exact same motor, and had the exact same problem. I replaced the bulb, and have had no more problems since.

Not to hijack your thread, but while we're on the subject of old 80 hp Mercs; can anyone tell me if automotive spark plug wires are suitable for use on one? OEMs are so danged expensive.
 
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oldman570

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

Plug wires have to be stranded copper core or solid wire and the automitive wires are not. Stranded core or solid core wire can be bought at most automotive stores by the foot and cut as needed and new ends put on them. Cheaper than new Merc wires.
 
countryboy26047

countryboy26047

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

oldman570 said:
Plug wires have to be stranded copper core or solid wire and the automitive wires are not. Stranded core or solid core wire can be bought at most automotive stores by the foot and cut as needed and new ends put on them. Cheaper than new Merc wires.
Click to expand...

Ya beat me too it oldman... however I'll add one thing. I, too, wanted to change my plug wires in my merc 850 whenever I put the new plugs in, but couldn't stomach the price for the factory ones. I went to three different auto zones, two advanced auto's, and two napa's... NONE had the solid OR copper strand wire either in precut lengths, or in 'bulk'. I had planned on just ordering the wire kit off the internet, but have gotten so side tracked with everything else life (and this friggin boat/trailer) has been throwing at me.
 
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Dave1027

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

packer_fan_46 said:
My 80hp Merc will start and idlle, it will go to WOT without problem and stay there, however, when I shut the engine off to retreive a skier, the motor will not restart. It will turn over, and almost start, and then will stop. I repeat this numerous times, each time it almost starts, then quits. Eventually, the motor will restart.

I just purchased the boat this summer, and the previous owner burned alcohol gas in it, which is a no no for this vintage of motor. I am thinking it is a fuel pump issue, maybe a kit is needed? Thanks. The motor is on a 1984 Sea Nymph Fish and Ski, nice boat.
Click to expand...

I think the first thing to check is the idle mixture adjustment of all carbs. If all you are doing is turning it off and back on within a few minutes it should fire up instantly. No need to choke or even pump the bulb at that point. Now if the motor is turned off for an extended period say more than 5 minutes then that would mean the gas sitting in the carbs may have had ample time to settle and dry out. In that case I always verify the bulb is pumped and may even have to hit the choke a tiny bit.
 
backlashed

backlashed

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Messages
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Re: 1983 80hp Merc. Will not restart easily after warmed up?

countryboy26047 said:
Ya beat me too it oldman... however I'll add one thing. I, too, wanted to change my plug wires in my merc 850 whenever I put the new plugs in, but couldn't stomach the price for the factory ones. I went to three different auto zones, two advanced auto's, and two napa's... NONE had the solid OR copper strand wire either in precut lengths, or in 'bulk'. I had planned on just ordering the wire kit off the internet, but have gotten so side tracked with everything else life (and this friggin boat/trailer) has been throwing at me.
Click to expand...

I called around today, and found that our local Oreilly's has bulk wire and all of the components.
Thanks again
 
countryboy26047

countryboy26047

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

backlashed said:
I called around today, and found that our local Oreilly's has bulk wire and all of the components.
Thanks again
Click to expand...

Glad you had better luck than me!! Wish we had an Oriellys around here!
 
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oldman570

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Re: 1983 80hp Merc. Will not restart easily after warmed up?

Might try a local lawn mower shop or a farm supply store for solid core wire also.
 
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