I have a 1984 50 hp Mercury with no spark on cyl. 3 & 4.

H​I Mike. I'm actually not available for a phone call at the moment. But I got the serial number, ran it. And on your ignition system, there are only 4 things that can cause no spark on 3 and 4. Those four things are

1. a bad power pack.

2. bad trigger coil

3. 2 bad ignition coils

4. 2 bad spark plugs.

1. I see that you replaced the stator (That would not cause lack of spark to 2 cylinders. The stator powers the entire ignition system. If the stator was bad, you would have no spark on all cylinders)

2. swapped coils

3. I don't see any mention of new spark plugs?

4. Last on the list is changing the trigger coil. Did you do that?

O​kay then basically change the plugs first and see is spark returns on those 2 cylinders or not. (It would be uncommon for 2 plugs to die at once, but it has happened. Otherwise, if those plugs are new and good, the problem can only be a bad trigger coil. Replace that and you will have spark back to those cylinders. Does that all make sense. I think that should do it. But I work for tips so I do want to make sure you are happy with my service before you go. If you had a further or more specific question on the issue by all means feel free to ask. If not, Just in case you do not understand the way the website works (and some folks do not). You do have to put forth a positive rating in order for it to credit me for helping you. When ratings are not done, the website simply keeps your deposit and they will not credit me. The ratings box is located at the top of the screen. To rate, you must select the star you wish and also confirm it. Please let me know if you run into any problems or errors when trying to do it. If you do have a problem, or if you can not see the ratings box which is at the top of the screen. Please reply back "I rate Jason's service _______" and fill in the blank.

Questions do not close out, so if you have to come back later on with follow up questions to the issue you still can even after doing a rating.

Thank you
Jason

It is under the flywheel.

T​he stator and the trigger are both in under the flywheel. When that flywheel is removed there will be 2 sets of coils. The inner coil, the one closest to the crankshaft, is the trigger coil.

You are very welcome. Thanks again. -Jason