1987 50 HP Johnson Will Crank But Not Start

Hey guys. At the beginning of the day today my motor would not crank or start.

I spent the whole day tracking down the issue and narrowed it down to an electrical problem. After finding out which wire was causing the problem, I replaced it and reconnected everything and got it to crank! After trying to start it about 8 times, I gave up.

To give you a little backstory on the motor, I purchased the boat (16 ft. 1987 Monark) about a month ago. When I purchased it, motor was running great. Then I immediately started gutting and stripping the boat, preparing for a paintjob. I removed the motor and leaned it up against my fence, upright and placed a tarp over it. That's where it has sat for the last month before I bolted it back onto my boat yesterday.

What things should I check to try to narrow down the problem? Not too experienced with motors and doing work on them. Thanks so much for your help guys!

Took it off and left it to drain and go dry?
My first impression is fuel delivery. Things like o-rings don't like to dry out. Even a tiny crack in one that was formerly wet can cause leaks and fuel delivery issues.
I know from personal experience the fuel tank connector seals (o-rings) are very sensitive to this.

But I'm learning - I don't even own an outboard! Just throwing it out there.

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I would be looking at electrical.

do you have spark? First thing to check.

when you say you replaced that wire, what happened to it that it needed replacing?

maybe there are other wires that got damaged or not hooked up (or hooked up incorrectly) you are overlooking

thats where I would be looking since it ran fine before you removed it

Ignition kill circuit? That will cause it to crank, but not fire ...

Yeah I kinda overlooked the whole "gutted and stripped" part of the scenario.



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DaleH said:

Ignition kill circuit? That will cause it to crank, but not fire ...

Click to expand...

This would be my first check for sure. If that seems ok, check your spark. First checking it by just putting the spark plug against the head is acceptable at first. If you have spark there need to do a true air gap spark test. However, If no spark from the basic test (on any cylinder) then there is a kill switch problem you missed or a bad ground.

Thanks y'all for the help. Checked spark plugs today. One of the cylinders spark plugs was not firing. I replaced the spark plug wire and got it to spark. So now both plugs are sparking. I plugged them back in and tried to start, still no luck. Any other ideas on what to do to fix it?


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do you smell gas? It is flooded or not getting gas?

you never did respond to my other comments so I don't know

Engine requires -

Fuel
Air
Spark, properly timed

Getting fuel?
Spark timing correct?



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dahut said:

Engine requires -

Fuel
Air
Spark, properly timed

Getting fuel?
Spark timing correct?



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Click to expand...

it also requires compression to fire

not saying this motor has bad compression.

Just adding to your statement

Dumb question, does your control require the little black safety clip with the red spiral lanyard at the key?

Yours right that's actually primary
Fuel/oxygen mix, next
Then, properly timed spark.

I was just reading that last night. My thinking was just a little off - thanks for the correction!

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If you have spark try squirting a little gas in the spark plug holes then screwing them in and cranking. If it fires you have a fuel delivery problem, either your carb, fuel pump or an air leak in the system.