Nissan 40C CDI Pack Resistance Readings

[John_S]

I have an 80's Nissan 40C 2cyl 2 stroke. The coil/cdi pack has a Y-385 7C part marking, but believe it is Nissan #3406062601M. I did some resistance readings but can not find my manual (left at camp?). The secondary side has 2.7K on one plug and 2.6K on the other. The primary black and blue wire on connector is 65.8K. Nothing on black to red. Are those normal readings?

 

[pvanv]

Re: Nissan 40C CDI Pack Resistance Readings

There's a whole chart of ohm readings for the CDI on those. I don't have the service manual with me here at home, but 2.6 or 2.7 sounds normal on the secondary from memory.

What problem are you chasing?

 

[John_S]

Re: Nissan 40C CDI Pack Resistance Readings

I have had a gradual power loss over the last couple of years. Down about 5 mph at wot, and harder to plane. In the spring, I did compression readings. They were recorded in my missing manual, but were within the good range. The spark jumping at the plug does not seem as bright/hot as it once was. I did not test with a spark gap tool.

 

[Sea Rider]

Re: Nissan 40C CDI Pack Resistance Readings

lgnition Coil Resistance (?25%)
Primary Coil...0.2 - 0.3 Ω

Secondary Coil :
4.1 - 6.1 KΩ

Happy Boating

 

[John_S]

Re: Nissan 40C CDI Pack Resistance Readings

lgnition Coil Resistance (?25%)
Primary Coil...0.2 - 0.3 Ω

Secondary Coil :
4.1 - 6.1 KΩ

Happy Boating

Thx. Given it is working, I'd better remeasure the primary resistance. Am I correct that there is only one primary coil to two secondary coils? ie the blue and black wire to the exicter coil?

 

[Sea Rider]

Re: Nissan 40C CDI Pack Resistance Readings

Thx. Given it is working, I'd better remeasure the primary resistance. Am I correct that there is only one primary coil to two secondary coils? ie the blue and black wire to the exicter coil?

Don't have a 40 C at hand, on a 30 HP, near same black/yellow fron CD goes to Ignition Coil entrance, red-blue goes from CD to exciter coil, brown-black to stop switch. Ther's one pimary with 2 secondary ignition coils.

Happy Boating

 

[John_S]

Re: Nissan 40C CDI Pack Resistance Readings

Don't have a 40 C at hand, on a 30 HP, near same black/yellow fron CD goes to Ignition Coil entrance, red-blue goes from CD to exciter coil, brown-black to stop switch. Ther's one pimary with 2 secondary ignition coils.

Happy Boating

Mine has the coils and CD all in one black box. It does have the brown and black pair of wires to the stop switch. One short black ground wire that ties into the engine block. The two spark plug wires & boots, and a 3-prong connector that goes to the exiter coil. This 3 prong has a black, blue, and red wire. Black is ground and is tied internally to the short black wire.

I will recheck resistance this evening. Maybe, it is because I am reading through the CD unit and not direct to the primary side of coils.

 

[Sea Rider]

Re: Nissan 40C CDI Pack Resistance Readings

Newer 40-C have independent ignition coil and CD.

Happy Boating

 

[pvanv]

Re: Nissan 40C CDI Pack Resistance Readings

Be sure to use a quality ANALOG meter; Cheapie digital units will not show the whole story.

 

[John_S]

Re: Nissan 40C CDI Pack Resistance Readings

My old simpson analog meter is long gone. My good digital fluke is dead. The digital meter I have is certainly not high end, but not the dirt cheapo either.

I remeasured and get consistant readings on the secondaries. The blue to black (primary?) acts like it is reading through electronics. It is not a low ohm (less than 200) reading. I get 1.68K when negative probe is at black pin, open if you swap probes. Like reading through a diode.

Note: The higher reading in the 1st post was from leaving the meter on the same range from measuring the secondaries.

Maybe it is better just to use a spark gap tester.

 

[pvanv]

Re: Nissan 40C CDI Pack Resistance Readings

A spark tester may confirm poor spark, but won't nail down the exact problem. How are the exciter coil readings?