1987 Johnson 15 HP J15RCUD Lost Spark

Terrapin

Petty Officer 2nd Class
Joined
Jan 15, 2006
Messages
163
New to me 1987 Johnson 15 HP engine J15RCUD. I was told this engine hasn’t been run for 4 years. This engine has the newer style fuel pump p/n 399857, but early style carburetor with metal bowl. I understand this was a transition year for the new fuel pump and carburetor, but the carb is the older version.

On Saturday compression check on both cylinders = 112 psi, Spark on both cylinders jumping 7/16” gap. Engine fired up, ran and I purchased the engine.

Sunday, I placed the engine in a barrel and ran on new ethanol free gas with Stabil, Yamaha ring free and Mercury Quickleen normal dosages. Engine started shifted and ran fine for approximately 20 minutes with heads heating up to 163 degree F. Water pump seems to be working, but I plan to replace the impeller. I also plan to rebuild the carb. Engine died approximately 5 minutes after reaching 163 degree F

This 1987 15 hp has the cable type throttle with red kill button on end and man overboard lanyard switch on end.

No spark at either cylinder at this time. Any guidance on next steps to regain spark.
 

Terrapin

Petty Officer 2nd Class
Joined
Jan 15, 2006
Messages
163
I have the “CU” 9.9 thru 30 Service Manual and performed the following tests:

Stop Switch Test – R and TE Models:
Meter correctly shows NO continuity with clip and lanyard installed.
Meter correctly shows continuity when stop switch assembly is pushed in.
Meter correctly shows continuity when clip and lanyard are removed.

Stop Circuit Test: I did not perform this test since I don’t have the “jumper wires” to make reliable pin connections. The above Stop Switch Test results should confirm functionality? Correct?

Charge Coil Ohmmeter Tests:
Charge Coil resistance is 563 ohms and within 575 +/-25 ohm range
Ground Tests: No needle movement (infinite resistance) testing charge coil lead “A” and “D” to ground

Sensor Coil Ohmmeter Tests:
Sensor Coil resistance is 39 ohms and within 40 +/-10 ohm range
Ground Tests: No needle movement (infinite resistance) testing sensor coil lead “B” and “C” to ground

I don’t have a C.D. Voltmeter, “Terminal Extenders” for the ignition coils, or a “Junction Box” for run tests, but I plan on completing the Cranking Tests using a friends Klein CL800 clamp on meter which I am told can read peak voltages. Will this meter work for these tests?

Any other thoughts on any additional tests or checks I should perform to find the root cause of my NO SPARK problem?
 

Terrapin

Petty Officer 2nd Class
Joined
Jan 15, 2006
Messages
163
Where is the ignition module on that? Disconnect the black kill wire from the module
I believe the black kill wire is the "E" terminal on the 5 pin Amphenol connector. If I understand, you are suggesting the "Stop Circuit Test" in the manual. Thinking I performed the "Stop Switch Test" to confirm kill circuit functionality, I was reluctant to pull the "E" pin from the Amphenol connector. Could I accomplish the same test by more easily removing the ground wire from the engine block/ground?
 
Top