1985 Mercury 25XD firing problem

Hey guys, I’m new here and I have a question I hope some of y’all can help me with. I’ve got a 1985 Mercury 25XD that I just picked up and I’m hoping to get it going. I went ahead and completely went through the carb and found some issues there but now it seems that I’m not getting any fire to the top cyl(#1). I was told by the previous owner that he thinks it was a bad stator. It had a new CDI put on it in 2011 but I’m not eliminating that as an issue either. I used a spark checker and the bottom cyl has fire but the top cyl was dead or almost dead. Swapped coil packs and the issue was the same. I guess my question is, would the stator cause just 1 cyl not to get fire or would that be due to a faulty CDI? Any input is greatly appreciated!

More than likely your cdi is the problem. Those motors have a single trigger for both cylinders and are pretty durable units. Go to www.cdielectronics.com for the ignition troubleshooting guide.

Ok so I just got out there messing with it some more and went ahead and pulled the flywheel off. I actually found a wire coming out of the stator that was cut into. I went ahead and ordered one from eBay so hopefully that fixes the issue

I changed the stator today and still no fire to the top cylinder. I checked the coils according to a spec sheet I have and they are both good. I’m guessing it’s time to purchase a new CDI but first does anyone here know if there is a way to check it to be certain that is my problem?

You need to use a DVA meter. You can buy an adapter (Amazon, about 30 bucks) for a conventional meter to do the testing.

Clamp onto the stator wires and spin her over. If the stator is okay you'll get the proper reading.

Using a DVA (my latest and favorite tool!) is the only way to check a stator out. You can also check the output of the switch box and what happens when the juice gets to the coils. Usually pin points the problem immediately.

Jeff