1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

rjswenson

Cadet
Joined
Jul 19, 2013
Messages
10
1960 Evinrude 40HP - Model 35520 - electric start - no generator.

Will not start - no spark after cleaning the fuel pump reservoir????

History:
Last week I rebuilt the carb as the engine was not running smoothly. Had it running yesterday (started and ran fine - a little rough). Last night I removed the fuel pump gas reservoir to clean it and to check the filter. That seemed fine so I put it back together. This morning, the engine has no spark!!!!!

Have checked for spark in the following ways (grounding the spark plug case on the engine and observing for spark):
1. Removed the wiring harness from the starboard side of the engine and pulled on the starter rope. No spark.
2. Replaced the wiring harness, cranked it over via the key, no spark.
3. Removed the two wires from the Vacuum Cutout Switch and cranked it over with the key. No spark.

Can anyone give me a clue as to what happened? Did I bump some mysterious electrical connection that would prevent this thing from sparking????
 

Big Jay

Petty Officer 1st Class
Joined
Aug 7, 2012
Messages
244
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

You'll have to pull the flywheel and check the ignition, could be something under there has expired with impeccable timing...

Are the plug wires original? Maybe they've finally given up.

Either way, pull the flywheel.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

Ill assume you tested both leads? No spark on either?

Do you have the 2 black leads coming from under the flywheel hooked up to the M terminals of the key switch? Have you tried disconnecting them and trying again? Any frays in those leads?
 

rjswenson

Cadet
Joined
Jul 19, 2013
Messages
10
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

Ill assume you tested both leads? No spark on either?

Do you have the 2 black leads coming from under the flywheel hooked up to the M terminals of the key switch? Have you tried disconnecting them and trying again? Any frays in those leads?

Thank you for replying.
Yep - both leads were checked.
I will check these wires per your suggestion a report back.
 

rjswenson

Cadet
Joined
Jul 19, 2013
Messages
10
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

New Info:

Disconnected the knife connectors between the mags and the starboard side wire harness socket. Still no spark (hand crank or key).

Disconnected the knife connector between the mercury switches and the starboard wire harness socket. Still no spark (hand crank or key).

Checked for cross linked wires in socket connector - none found. Made sure both wires from mags were only going to individual pins in socket. Made sure starter wire was connecting only to an individual pin in socket. Made sure mercury switch wire as connecting only to an individual pin is socket.

Found an interesting article at
http://assets.fluke.com/appnotes/electricalpower/B0271b_u.pdf
titled: "Troubleshooting Outboard Motor Magneto Ignitions". It detailed how to do a Coil and HV wire resistance/continuity test. So, following the article, this is what I did: "touch one probe tip to the engine block and the other to the metal connector inside the plug wire cap. The meter should read the resistance of the coil and HV wire in series. Good readings will range from 3Kohms to 15Kohms. Results: top cylinder wire read "OL" while to bottom cylinder wire read "6.43Kohms". Still no spark on either wire....

Sounds like the top wire has a break somewhere (shows "OL" on meter). But shouldn't the bottom one have a spark (shows 6.43Kohms on meter)?

Don't know what else to check. Next comes looking under the flywheel???
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

You are essentially testing the secondary winding of the coil, as well as the plug lead. You have a break somewhere there. Usually at the pin itself. I forget, have the coils been changed?

have you already tried cleaning the points?
 

rjswenson

Cadet
Joined
Jul 19, 2013
Messages
10
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

Thank you for your responses, they have been very helpful. Well, I took off the flywheel and found the key had been sheared..... not sure how that relates to this problem. I am now into the ignition system (should be fun).

Thanks again
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

The sheared key (I thought so) throws off the timing relationship between the flywheel magnets and breaker points' opening. Therefor no spark.

OK, now find and fix that coil continuity problem. Then install the flywheel PROPERLY. If that had been done last time, it wouldn't have sheared. Flywheel and shaft tapers and keyways must not be buggered up. Tapers must be clean and dry. You must use a torque wrench to tighten the nut to 100-105 foot pounds.
 

rjswenson

Cadet
Joined
Jul 19, 2013
Messages
10
Re: 1960 Evinrude Lark 40HP - no spark after cleaning the fuel filter bowl??

Found the problem of the upper cylinder not firing - the spark plug wire going to the coil was broken. I think this thread is resolved.
Thanks again for all your help.
 
Top