No spark 4hp Mercury 1978 model Twin cylinder

[colsan]

I have no spark at the spark plugs, I purchased new plugs & still no spark.
there is a reading within specs on the ohm meter on 2 wires coming from trigger assy (brown & white) under the flywheel & going to the switch box (Thunderbolt 11) but no reading on the wires going from switch box to starter coils. I am not sure if the problem is in the stator, coils or switch box.
serial number of motor is 9188880 & the number on the switch box is P/N 339-6222A8 and has a date of JUL 25 1977 on rear of switch box, it is a model Gnat ML.
happy for any suggestions on how to diagnose probable parts that maybe causing the problem.
colsan

 

[mc66]

Re: No spark 4hp Mercury 1978 model Twin cylinder

I had an issue with a 1978 20hp merc no spark. The brown and white wires were factory spliced together. Cut open the splices and both wires were rotted cut back wire respliced and spark was restored.There was enough wire left dident need to add any. Hope this helps

 

[Laddies]

Re: No spark 4hp Mercury 1978 model Twin cylinder

Here's the simplest and most accurate test, use it and quite talking about it.