late 70's 40hp evinrude issues

Purcell1

Cadet
Joined
Sep 18, 2012
Messages
20
Hello all,
I have aquired a 14' runabout with an older 40hp on it. The engine has not run in a few years. The problem i have is i don't have a key for the ignition switch, so when i brought her home, i tried to get it started.

Due to not having a key, i applied 12vdc directly to the starter motor. Sure enough the starter popped up and turned her over. Would not fire up however. Fuel seems to be getting past the filter.
I pulled the spark plugs and did not see spark, but they were dark and wet so it appears there is fuel there.

My real question is, by bypassing the key switch, will this still allow the motor to fire? i understand there are two wires from under the flywheel which run to the key switch and act as a kill switch?

Tomorrow i will go back and pull the flywheel and clean up the points and check for spark again, but i just want to be sure im not chasing around for no reason if it has to do with the switch.

Thanks!
Kevin
 
Joined
Apr 28, 2013
Messages
186
Re: late 70's 40hp evinrude issues

Your key switch is off so no power see if u can acess behind key switch and hook wire straight but not the one that starts it right now no fire because of that thats how i did my mopad see if you can take switch off and get keyed for like 30 may be able to hot wirefrom engine but not forsure if ground will have to be hooked straight too
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: late 70's 40hp evinrude issues

Keyswitch has to be "On" for motor to fire. You can disconnect the kill wires from the switch and then jump-start it. Then you will get spark.
 

Purcell1

Cadet
Joined
Sep 18, 2012
Messages
20
Re: late 70's 40hp evinrude issues

ok, so if i disconnect them att he starter switch, and then just jump it at the starter motor it should spark? providing the points and all is ok?
Thanks for the input.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Re: late 70's 40hp evinrude issues

Yes you can rig it up to start and run but be warned that you will no be able to shut it off as well with out the key switch connected up unless you stop either the spark or the fuel...
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: late 70's 40hp evinrude issues

Easier than crawling under there to access the switch, simply disconnect one of the two black wires coming from under the flywheel. Then you can stop it by touching the wire terminals back together.

We are assuming in all of this that you have a magneto ignition motor. "Late 70's" is kind of vague. EDIT: Actually, a 40hp magneto motor would be early '70s....or older, clear back to 1960.
 

Purcell1

Cadet
Joined
Sep 18, 2012
Messages
20
Re: late 70's 40hp evinrude issues

hey guys,
so info on the motor...
Johnson 40EL74S serial: C39095

So i would assume its a 74' year. So i went and bought a new ignition with key (50$!!!) and installed it. Sure enough, she turns over just fine. Moving on, i pulled the plugs and they were dark and wet with fuel. So i did a spark test and found the lower plug sparks good, but the upper one was not, so i swapped plugs, and the top one seemed to work, but a little faint. I would think it would still fire, just run rough?

So i will be buying to plugs, pulling the flywheel, and cleaning the points. Maybe then we can get it to fire up!

Does anyone know what size nut is on the flywheel?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: late 70's 40hp evinrude issues

If I remember correctly, 1-1/16". You must use a torque wrench to tighten it to 100-105 ft lbs when you put it back together, or kiss it goodby.
 

Purcell1

Cadet
Joined
Sep 18, 2012
Messages
20
Re: late 70's 40hp evinrude issues

will do, thanks! any advice on how to lock the flywheel to keep it from spinning when torquing
 

Purcell1

Cadet
Joined
Sep 18, 2012
Messages
20
Re: late 70's 40hp evinrude issues

also, im an idiot, it's a johnson, not an evinrude. Not that it matters much.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Re: late 70's 40hp evinrude issues

Not sure if you ever tried to remove a flywheel on an outboard but you are in for some interesting work. Before you even start, go buy some grade 8 bolts that fit the threaded holes in the top of the flywheel. And get a good flywheel puller or get a loaner from an auto parts store. Remove the nuts from the top of the flywheel and let the fun begin. Thread those grade 8 bolts in about 7/16" deep while attaching the wheel puller. Then take a really good breaker bar and start tightening the center bolt to remove the flywheel. It is on there really tight and seems like it will not come off. Others have used hammers, mallets and even some heat to try and loosen that flywheel. I had to use a pneumatic impact wrench to get mine off. But be careful and it will break loose eventually... Usually when it does break loose it will make a loud bang and you may even think you broke it... But it will be okay and in one piece... Just some forwarning for you.
 
Top