No spark !!!!

[Billy weirzler]

1986 MerCruiser 170 just did a motor swap from a 180 to the 170 everything hooked up everything put Together and now we have no spark checked all wires traced wires no spark I am getting power on a test light to the positive and negative side of the coil with the Key on.

 

[Bt Doctur]

With the test light is there constant 12v on the + side and is it blinking on and off on the neg coil side

 

[Billy weirzler]

No full light

 

[nola mike]

No full light

While cranking? And are you still running points?

 

[Bt Doctur]

that means the points are not grounding out when the rotor is turning

 

[Billy weirzler]

While cranking? And are you still running points?

Yes

 

[Billy weirzler]

Why would the points not ground out

 

[Bt Doctur]

for spark you need power at the + side and a momentary closing and opening of the points.Remove the we from the neg side of the coil , install a jumper with enough we to reach a good ground. With key on, strike /scratch the wire along the block, you must produce spark.
If yes then the points are badly oxidized and not making a connection with each other

 

[Scott06]

BT has you steered straight -clean and file the points set with a dwell meter once you get it running. When properly maintained points are just as good as any ignition system, but this is why they did away with points too much maintenace.