FD-10 1956 15hp Johnson potential spark issue

[Drowned Rat]

Hi guys,

I've got this motor running, what I haven't looked at yet was the coils until now. My top clyinder seems fire always and pefectly. The bottom cyclinder fires only when it wants to.

Is it worth replacing the coils on this motor??

Thanks so much for all your help!

 

[oldboat1]

Re: FD-10 1956 15hp Johnson potential spark issue

sounds like a coil, but check out the plug wire boot first. There is a spring connector up inside the boot. That's the electrical connection for the plug (tip of which goes into the spring). That connection has to be clean and shiny. I use a phillips screwdriver to clean it up without removing it from the boot -- try that first to see if it takes care of the intermittent spark problem.

I don't know if you have removed the flywheel yet, but the coils, points and condensers are under there. If there is an inspection plate on top of the flywheel, take that off and look down at the top of the magneto plate. Typically, old coils will have cracked housings, which are easy to see. If you see cracks, plan on replacing the coils -- may need to anyway, but definitely should if they are cracking.

Anyway, that's a start. You can rebuild the magneto with new parts (incl coils) for about $100, give or take.

 

[kfa4303]

Re: FD-10 1956 15hp Johnson potential spark issue

+1. The stock OMC coils have a 100% failure rate over time. Here are some handy links that can walk you through an ignition rebuild and overall tune up.

Maintaining Johnson E & FD Serie
3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

 

[Crosbyman]

Re: FD-10 1956 15hp Johnson potential spark issue

good strong motors worth fixing if no major issues (parts available & not to expensive)

easy to convert to pump (sorry purists) but you need to change the side connector to a single line connector.

 

[oldboat1]

Re: FD-10 1956 15hp Johnson potential spark issue

ouch! I'm wounded with the fuel pump thing....

Crosbyman is right. When you get up to fuel issues, you can convert to a fuel pump if you want. Depends on what your plans are for the motor (antique restoration, for example?) You can convert back to the pressure tank system later, though, so putting on a fuel pump isn't a permanent change. If you do it, I suggest getting a second exhaust cover somewhere and putting the fuel pump on that (requires a hole in the cover). That way, you can put on the original cover if you want to convert back.

 

[racerone]

Re: FD-10 1956 15hp Johnson potential spark issue

I do believe the fuel pump fits on one of the 2 intake covers !

 

[oldboat1]

Re: FD-10 1956 15hp Johnson potential spark issue

yes, actually goes on the bypass cover, where the pump gets a pulse. Downed Rat -- If you get up to that, you will be checking for detailed instructions (a number of discussions, here and elsewhere).

 

[kfa4303]

Re: FD-10 1956 15hp Johnson potential spark issue

The fuel pump conversion is well worth the effort and east to reverse if need be. Mikuni seems to be the brand of choice for pump, unless you have the $ for an OEM part. Here are some links that may help.

HOW TO CONVERT 50s motors from two line tanks - YouTube
Converting the Old OMC Dual Fuel
MIKUNI SINGLE FUEL PUMP from Aircraft Spruce

http://forums.iboats.com/johnson-evinrude-outboards/grandads-johnson-seahorse-10-a-506678-2.html

 

[Crosbyman]

Re: FD-10 1956 15hp Johnson potential spark issue

if you convert to pump I suggest you look at B&S round pumps (cheap)

 

[tjandrews]

Re: FD-10 1956 15hp Johnson potential spark issue

Definitely worth replacing the coils if needed, but there's still the possibility it could be something else. My '54 10HP started running like that a couple of years ago, with coils known to be good. It would run fine for a few minutes, then one cylinder would quit. I cleaned and set the points as carefully as I could, no dice. New condensers, no dice. Turned out to be one of the spark plugs, even though they only had a few hours on them. It was crapping out as soon as it got up to operating temperature. New plugs did the trick.

 

[oldboat1]

Re: FD-10 1956 15hp Johnson potential spark issue

I had a similar experience last summer in working on a motor -- had spark verified with a spark tester, but ended up replacing a plug to get the motor up and running. Recalling (incorrectly maybe) that I had no continuity on the plug I needed to replace, and had not seen that before (top of plug to center post).