chasing no spark issue

[Alumarine]

Hi there. I'm really hot, really tired and really hungry and I got a no spark issue.

Went to fire up my 74 Mercruiser 140 for the first time this year and no spark.

Fired up fine last fall. Brother in law borrowed starter and temp gauge to try in his boat. May have wiring issues now.

This system uses an external resister type coil
Resister wire checks out ok from the coil to the large wiring plug.

Have 12 volts on the ignition/resister wire. Thought I should have less.

Tried to hot wire it by running 12 volts to + side of coil. No spark.

Just have ignition wire and starter wire to + side and distributor to - side.

Any suggestions? Is it ok to run 12 volts direct to coil for a short time?

Thanks - gonna take a break from the sun.

 

[Bt Doctur]

Re: chasing no spark issue

for testing, Yes. Check the points to make sure there not "glazed over" from sitting.
check the gap .018 , a shorted condensor, a bad tach will kill spark, remove the grey wire from the neg side of the coil. Shiftinterupter switch can ground out the spark too.

 

[TiredoleBoy]

Re: chasing no spark issue

Have you looked at the points? Is the circuit breaker OK? If I am not mistaken there should be a wire running off the starter solenoid to the coil. Is this OK?

 

[Alumarine]

Re: chasing no spark issue

Thanks guys.

Tach and shift interrupt are disconnected.

Have ignition wire and wire from solenoid going to + side of coil.

Only wire on neg. side is going to distributor.

Will check points again.

Condenser is new.

Get spark from coil when I short the neg. side to ground.

 

[achris]

Re: chasing no spark issue

Get spark from coil when I short the neg. side to ground.

That would point to points....

 

[TiredoleBoy]

Re: chasing no spark issue

Thanks guys.

Tach and shift interrupt are disconnected.

Have ignition wire and wire from solenoid going to + side of coil.

Only wire on neg. side is going to distributor.

Will check points again.

Condenser is new.

Get spark from coil when I short the neg. side to ground.

Sounds to me either the condenser is bad ( yes new parts do go bad) or the points are grounding out.

 

[Alumarine]

Re: chasing no spark issue

Great, will try another condenser.

How do the points ground out - the wire?

 

[TiredoleBoy]

Re: chasing no spark issue

Great, will try another condenser.

How do the points ground out - the wire?

The wire could be touching ground or..... the points themselves have an insulation washer on the spring. This may be bad as well. Take an ohm meter and when the points are open touch the wire at the points and then touch the other to ground what is the resistance? It should show an open circuit.

 

[Alumarine]

Re: chasing no spark issue

Thanks guys. Sanded points and replaced condenser.

Fired first click.

thanks again