Newbie 57 FD 11 Backfires

Joined
Apr 9, 2009
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24
I just picked up a few old johnson motors from a friend. I am really having issues with my 57 fd 11. I wanted to make sure that the carb, tank and lines were in good condition, I replaced the coils and points, ck'd and gapped at 0.20. I wanted to make sure that most of the motor was in good shape before trying to even start it. I tried to start it today and it just backfires and dies. I don't have a manual or know much about outboards so any ideas would be great thanks.
 

Xcusme

Commander
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Apr 21, 2003
Messages
2,888
Re: Newbie 57 FD 11 Backfires

Hmmm....I hope that was a mistype..the points should be .020..not 0.20. Check the flywheel key for being partially sheared..
 
Joined
Apr 9, 2009
Messages
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Re: Newbie 57 FD 11 Backfires

Yes that was a typo sorry. The key looks like there is a light step in it. Should it also be snug to the flywheel when its put back together? I don't know a spec for what the size should be but will call the shop tomorrow to see if they have one avail. or if I can match it up thanks.
 

lindy46

Captain
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Nov 27, 2008
Messages
3,886
Re: Newbie 57 FD 11 Backfires

Check compression and check that you're getting good spark. Also, make sure your tank is holding pressure - that motor has no fuel pump and relies on tank pressure to push fuel into the carb. If all that is okay, then it's time to clean and rebuild the carb.
 
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Apr 9, 2009
Messages
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Re: Newbie 57 FD 11 Backfires

Yeah looks like i need to figure out how to fix or replace the tank first. I did manage to get it to run long enough to see that at high idle the motor runs real smooth. As soon as i set the throttle down to idle speed is when it starts to backfire and quits on me. I didn't pay a whole lot for this motor and would hate to put a ton into getting it to run. I see that there are alot of people with alot of faith in these motors but with parts being hard to find and as old as this motor is, is it worth the effort?
 

EN2

Chief Petty Officer
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Nov 19, 2007
Messages
404
Re: Newbie 57 FD 11 Backfires

Even if that key looks suspect I would replace it. Dont know what the torque spec for your model is, but it needs to torqued to specified amount. Someone here will come in with it.
 
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Apr 9, 2009
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Re: Newbie 57 FD 11 Backfires

Thanks for all the help, I'll look into the key and spec for the torque. Then I will try to fix the tank, if thats possible. Last question, there seems to be some light corrosion around the head gasket. If I get the chance I'll get some pics. I don't really know what else to look for.
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: Newbie 57 FD 11 Backfires

Does it "backfire" or sneeze/cough. There is a big difference. A backfire suggests a sheared flywheel key putting the timing off or maybe preignition due to carbon buildup...a sneeze suggests a fuel issue.

MAS
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: Newbie 57 FD 11 Backfires

The flywheel torque is 45ft/lbs.
It has to be an OMC flywheel key, so don't go the hardware store route.
However, if it runs good on high idle, I don't think it's because of a bad key.
I believe you are having problems with your carb. It needs to be cleaned and adjusted correctly. There's a super thread on this in the "top secret stuff" on the top of this forum. Also, is the motor backfiring or is it lean sneezing. There's a big difference. Also, do you have the carb. and armature plate synchronized? When the throttle cam roller passes the 2 marks on the armature cam, the throttle plate in the back of the carb should just start to open.
Don't worry, you'll figure it out.
JBJ
 
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Apr 9, 2009
Messages
24
Re: Newbie 57 FD 11 Backfires

OMG, I didn't realize there was so much to this. I guess you could call it a cough. I guess that would be a nice start. Also any tips on fixing the tank?
 

asdasc

Senior Chief Petty Officer
Joined
Aug 28, 2008
Messages
680
Re: Newbie 57 FD 11 Backfires

What is wrong with the tank? Then we can tell you how to fix it.
I assume it is a pressure tank? Does it hold pressure when you pump the little button on the top? If it doesn't leak, it can be cleaned and rebuilt using kits available online. I want to say it is laingsoutboard.com that has them.

Can someone confirm I am remembering this right?
 
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Apr 9, 2009
Messages
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Re: Newbie 57 FD 11 Backfires

I guess I should have stated all things from the start. I got the 57 seahorse from a friend for $100. I tried to make sure the motor was in pretty good condition before I tried running it. Checking the plugs, points, ect. When I first started the motor I got the coughing and noticed the armature plate was really worn. Thinking that was my first problem, I bought a newer one on ebay. Upon replacing the plate I noticed that the connecting rod for the original plate was bent straight. The newer one was a nice half moon. Tomorrow I will check the carb out better. Look for a kit for the tank, which is spiting fuel from the push button when priming the tank. I will let you know how it goes tomorrow.

THANK YOU ALL SO VERY MUCH FOR THE INSIGHT
 

OldJohnson6hp

Seaman
Joined
Mar 19, 2009
Messages
53
Re: Newbie 57 FD 11 Backfires

"is it worth the effort?"

Yup..don't give up on it. These guys here are great and can walk you through any problem. Go through it and you'll be running a basically brand new motor that will last ANOTHER 50+ years!
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Newbie 57 FD 11 Backfires

Check the flywheel key...could be sheared and out of time. Pull and clean the carburetor...a dirty idle/slow speed circuit will cause it cough/sneeze. If the key is toast, you need an OMC/Johnson key...not a soft hardware store key. Sounds like your carb is mucho dirty if you put everything back in place right and key is intact when you changed the coils.
 

rjezuit

Chief Petty Officer
Joined
Sep 24, 2007
Messages
418
Re: Newbie 57 FD 11 Backfires

Try laingsoutboards.com for a rebuild kit for the tanks. There are two types depending on whether the prime button is metal or not. Rick
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: Newbie 57 FD 11 Backfires

Have you checked the compression yet? What are the numbers?

I have the FD-11 parts manual I can email you if you PM me your email address.
 
Joined
Apr 9, 2009
Messages
24
Re: Newbie 57 FD 11 Backfires

This morning I removed the carb, tore it down and soaked it in cleaner. I didn't notice anything clogged, no residue, none of the ports were plugged. The only thing i could see was a light film around the bowl of the carb. Will pick up a rebuild kit just to be safe. I even rechecked the plugs. I noticed the top one had a little carbon while the lower was still soaked in fuel. Another thing i found was on the exhaust cover, I believe thats what it is, one of the screws were replaced with a bolt and siliconed, right behind the fuel filter. Which brings me to another thing, is there a element that goes in the glass? only thing in there is the screw on washer.
 
Joined
Apr 9, 2009
Messages
24
Re: Newbie 57 FD 11 Backfires

A huge thanks to all who have helped me. With the easter weekend and the fishing picking up I haven't had time to mess with the motor yet. Hopefully I can get back to it tomorrow afternoon. I am so glad to have run into iboats and the people here are awesome. Thanks Aagin!
 
Joined
Apr 9, 2009
Messages
24
Re: Newbie 57 FD 11 Backfires

Ok so I'm back at it. I found out that the fuel filter had been missing. Replaced that. I bought a rebuilt carb, installed that. Armature plate new coils, points, and wires. Still no luck keeping it running.
 
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