no fire on cylinder 3&4

I was having problems with my mariner 80hp staying running when I put it in gear under load it would just die. Then I checked the spark today and its not firing on 3&4. It has 4 separate coils so does anyone think that it could be 2 bad coils or is there something else that I need to check that powers those two coils? I was going to swap one of the suspected bad coils to the #1 cylinder spot to see if it had power there.

Re: no fire on cylinder 3&4

Going to possibly be a trigger under the flywheel or stator...you need to do the tests before replacing...Coils almost never fail especially a pair....

Re: no fire on cylinder 3&4

More likely the switchbox as the pairing is off, if a trigger it would be 1 & 3 or 2 & 4 and its not the stator....

Re: no fire on cylinder 3&4

Thanks for the heads up because I dont want to spend $45 each on coils if they aint bad. I am saying its cylinder 3&4 because the 4 plugs are straight in line with each other and numbered on the block from top to bottom as 1,2,3,4. And the bottom 2 spark plugs are not sparking and they are bright white and as clean as they were when I put them in. So you think I have a switch box issue, and the switch boxes are located on the opposite side of the engine from the coils and they are sandwhiched together correct? Also the trigger is what makes the coils fire after sending a signal to the switch boxes? And the stator is what charges the battery while the engine is running correct? Thanks!

Re: no fire on cylinder 3&4

Hey I had same problem awhile ago. It ended up being my harness wires that ran from the switchbox to the coils. I ended up replacing spark plugs, spark plug wires and coils before I found out it was my harness wires.

Also:
You can test if its your stator be doing the tests on the CDI electronics website. Its somewhere in on their support page.
Mine was switching my blue and blue/white wires with the red red/white wires. This would transfer power to the other cylinders if it is ur stator. I believe they also have instrustions on how to test other parts like ur switchbox

Re: no fire on cylinder 3&4

Thanks for the info. I printed off all the testing directions off the cdi website. I have called around and I have been told many different things. So now I am getting confused and starting to think I am fixing to have to put out a good bit of money.

Re: no fire on cylinder 3&4

It sure would be nice to find that I had a couple of bad wires.

Re: no fire on cylinder 3&4

I had the exact problem. Ended up replacing switch box ($228.00). ouch. Then found the same thing new in Houston TX for $119. Just changed yesterday, today cleaning carbs, then back in the water for test run.