Starting problem

[Mel T]

Just bought 85 3.0 L mercruiser it won't start, no spark at coil primary thermals check out ok with ohm meter and so does the secondary side but there's still no spark can anybody suggest what else to look at?
thank you so much for any help

 

[makomark]

Can you measure the voltage at the coil's "+" terminal, with the key on? Assuming the points, condensor and rotor are ok, it is very possible the resistance wire in the harness has failed or its crimp has gone bad...you can replace it or substitute in a ballast resistor...

 

[Mel T]

I have battery voltage at the + side with key on. Thanks

 

[Mel T]

Makomark can you tell me what the voltage should be, at the positive side of the coil?

 

[Bt Doctur]

around battery voltage at first, then the resistance wire takes over and it drop to around 9 ish.If its points and you dont have spark , the points are glazed over. sandpaper or nail file to clean and test for spark.
then replace them.

 

[makomark]

To add a bit to BtDr said: with the points open, you show see battery voltage between "+" post of the coil and ground; the same measurement will show 8-9 V DC if the points are closed (and the rest of the system components are ok)

 

[bondo]

around battery voltage at first, then the resistance wire takes over and it drop to around 9 ish.If its points and you dont have spark , the points are glazed over. sandpaper or nail file to clean and test for spark.
then replace them.

Ayuh,.... This gets My vote for Most Likely issue,....

 

[Mel T]

Thank you too everyone that repled, as it turned out the points were covered in oil. Cleaned them up as well as the dist. And it started right up.

 

[makomark]

Glad you go it running...now I'd suggest you find out where that much oil came from...