1992 18hp Nissan no spark

[dfrants]

this 1992 18hp electric start Nissan 2-stroke sometimes has no spark. Thinking it might be the kill switch/lanyard on the control box. which wires to the motor control this and how can I disable this feature?

 

[pvanv]

The kill wire is brown. Grounding it to black stops the ignition. Generic kill switches are available.

 

[dfrants]

Thanks you. if I disconnect the ground/black wire that should by pass it till I can get a new one?

 

[pvanv]

Disconnect the brown wire at the motor end; that way any short, etc., will not be in the equation, since you will have bypassed the entire kill circuit. Of course, you will need to stop the motor by running the carb dry or over-choking while you are testing. Since you have a Remote model, if you determine that the kill switch is flaky, you may want to get a genuine Tohatsu switch -- that way, you know it will fit.

 

[dfrants]

I picked up a universal kill switch. It has four connections 2 (I) Ignition, 2(M) Magneto. The old one has a brown and a black. Any idea which to use?

 

[pvanv]

Magneto. Grounding the brown wire kills the ignition. (Normally closed; opens when the clip is inserted).

The other setup works in the reverse: disconnecting battery from ignition stops those motors. (Normally open; the clip causes the switch to close). Not what this motor needs.

Did you diagnose a bad kill switch, or are you guessing?

 

[dfrants]

Guessing, and hoping. When I was first asked to help get it started I was told by the owner that they have been having trouble starting it for years. that when it wouldn't start, if you fidget with the kill switch lanyard and get it just right it would start. Which it did for me once. And ran very smooth. thought I had it "fixed". Since that one time it hasn't fired up again. It will turn over but no spark. Now i'm thinking that isn't the main problem...maybe the stator, power pack or coil?

 

[dfrants]

or the exciter coil.

 

[pvanv]

The NS18C2 (year is irrelevant) does not have a stator. It does have a CD, which can be tested. Again please diagnose, rather than guessing.

 

[dfrants]

the model number on this motor is NS18C2. Does the "S" stand for short shaft?

 

[Sea Rider]

Can you 100% assure that kill cord switch is working ok ? The S is part of the Nissan nomenclature, all are NS whatever number follows. You need to get a Service Manual and a digital multimeter that reads DVA volts to troubleshoot nicely all electrical/elctronic related parts.

Other formula is a extremely wild guess, unless you have in stock all the previous mentioned parts to swap and test indivudually till the culprit component is found kaputt. Usually it's the Ignition Coil or CD power pack that fails..

Happy Boating

 

[pvanv]

the model number on this motor is NS18C2. Does the "S" stand for short shaft?

NS is for Nissan.
In addition to the CD, there is an exciter coil, a trigger coil, and the ignition coil. Any of them could have failed. This motor is at least 25 years old, and few if any carb bits are available, so proceed carefully.

 

[dfrants]

replaced the cdi unit, now she has spark. in the process of cleaning the carb. need to find a new float valve needle for it.