Intermittent Spark- 1996 Johnson 25

dda140

Recruit
Joined
Jul 17, 2011
Messages
5
Hey All,
1996 25HP Johnson Tripple (J25RML_e_C.... or something like that, off the top of my head)
Motor runs good, then dies with minimal explination... often restarts immediatly after, one pull, sometimes I can get it before the boat really stops... Sometimes it won't run at all. Yesterday, no spark in the moring. Let the motor sit in the sun for 2 hrs. Spark came back, fired on first pull... later on, out on the lake (in the sun) won't start. Pullin the cord every 10 min or so as we drifted and rowed to the boat launch (caught 3 nice jack along the way :) ), Get it on the trailer and fires one pull... so, Its an intermittent no-spark condition...

What can I check. I don't have a wire diagram. Thinking possibly a short on the kill-switch still, maybe iron filings on the magneeto. I've got 4 wires from the mag (2 orange 2 brown) and I think 5 wires from the flywheel area for timing I think. I don't know how to test the mag or the ignition timing wires. Everything goes to or comes from "the Black Box"... ECU? ignition box? whatever you want to call it... I haven't touched the ECU yet, thinking of pulling my fly wheel off to check for metal burrs on the mag but don't know what else to check next time I'm in the "no-spark" condition. I dont think wires/plugs is the problem, the plugs look good and all three cylinders loose spark at the same time so wires are probably no the issue...

Also, removed the oiling system, and running mixed gas... Originally thought the boat was choking/bogging (over injecting oil)... minor detail...
 

fmalott

Chief Petty Officer
Joined
Jun 28, 2010
Messages
561
Re: Intermittent Spark- 1996 Johnson 25

yes you do have a short somewhere check all that you said and check the obvious the ground and your motor model #should be J25RMLEDC it won't be timing it would of back fired and it wouldn't run like you said when you have apark check for a short first
 

dda140

Recruit
Joined
Jul 17, 2011
Messages
5
Re: Intermittent Spark- 1996 Johnson 25

I have been through the wiring more than once... looking for the obvious... Is there anything I can check in the Ignition box? Can I test for a short on the mag (how else do magnetos fail)?
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: Intermittent Spark- 1996 Johnson 25

with the price of ignition components for your engine, it would be a good investment to find an omc factory manual, not seloc or clymers, either on ebay or outboardbooks.com....cdielectronics.com offers testing procedures in pdf form...it'll take some hunting, but they're on their website
 

hidef

Lieutenant
Joined
Aug 22, 2009
Messages
1,465
Re: Intermittent Spark- 1996 Johnson 25

Your outboard is a 25RMLED unfortunately the 25s and 35s aren't listed in the CDI troubleshooting guide however if you follow the steps for the V4 with Optical ignition ( OIS2000) it will guide you. The kill circuit is the yellow black wire it plugs into the middle of the power pack with the leads from the 3 sensors. When the engine wont start pull that plug first if it starts then your trouble is in the kill circuit. Since yours is a rope start you don't have to worry about the rectifier test.

You can get the service manual from marine engines also you really should get one.

http://www.marineengine.com/parts/j...hnson&section=Ignition+System+-+Rope+&+Ac
 
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