1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

[Jrods]

I bought a 18 HP Johnson that has been sitting for over a year (maybe longer) I started with taking apart the motor and cleaning everything, i cleaned all the carbon from the motor, i cleaned out the carb for old fuel, i serviced the bottom end, replaced the water pump, replaced the reeds and made sure theirs no water in the oil. I've put it all back together again, and put some fresh fuel in. I'm getting spark, good compression, and still wont start! I've checked: all passages in the carb, made sure the needles were seeded, I've checked all the hoses.. (i'm an automotive tech, however i'm new to working on outboard motors, so i know what it takes to make a motor run, "so i thought?!!" lol) I AM TRULY STUMPED!! Any ideas?

 

[HighTrim]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

In your title, it says it starts and runs for a minute, and then dies, but in the description you say that it wont start at all? I hate to be nit picky, but we will need to know which is the case to diagnose the issue.

 

[HighTrim]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

....another minor point, they did not make a 18hp in '56, what is your model number so we can verify a year/hp?

 

[kfa4303]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

Focus on one issue at a time. Once fuel, compression and spark are confirmed you can try starting it again. If it won't stay running that usually means it is being starved of fuel. I would re-check all the lines leading to and from the pressure tank for any leaks. This link may help too.

Maintaining Johnson E & FD Serie

 

[1946Zephyr]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

If it stays running, by squeezing the primer bulb and dies after you quit, then you likely have a fuel issue. What is the condition of the coils? Unless they have been replaced at one point, they are likely bad. Original coils from those years, have long since been in need of replacement.

 

[Jrods]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

"I GOT IT!" I re-checked my points and did find one point off, so i set & cleaned that. I replaced my coils (one of them had an obvious burn in it) & float needle. But here's the main thing; I found the key on the throttle rod was busted off so i had to fabricate a new one which was causing the magneto to move back and forth and throwing off the timing. I've fixed a Game fisher 7.5 HP, 2 Yamaha's one 8 HP one 25 HP, and a 1974 Chrysler 15 HP. BUT THIS ONE GAVE ME A RUN FOR MY MONEY!! I think it was due to a combination of several things and it sitting for come to find out years! Now.. on to a Evinrude 1953 15 HP!! Stay tuned..

 

[nwcove]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

good you figured it out.....but what model # is the motor? and welcome to iboats!!

 

[1946Zephyr]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

cool. You might get with mark in new jersey. He has a 53 Evinrude 15 as well.

 

[Jrods]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

cool. You might get with mark in new jersey. He has a 53 Evinrude 15 as well.

Model # FD-12 (Oops! Looks like a 1958?!) Thanks for the help/advice, i've read a lot of posts from people having boat motor problems and its given me ideas on things to check!

 

[nwcove]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

just curious.....why did you replace the reeds?

 

[HighTrim]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

just curious.....why did you replace the reeds?

Definately rare to need to change them, especially on the 50s omcs. I have a couple hundred motors, and I have only done it once. Was a '76 55hp though, it was spitting back at idle, making it hard to fine tune, not one of my older motors.

Yes, a FD12 is a '58

 

[kfa4303]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

I think the '58 is the best looking one of 'em all. Glad it's running again. Any pics?

 

[1946Zephyr]

Re: 1956 Johnson 18 HP Seahorse (Starts for a minute and dies!) S O S !!!

Cool deal. I happen to own an FDE-12. Nice old motors and tough as nails. Once properly tuned, they'll run forever.