i was idleing down the lake in my pontoon boat when all of a sudden my 30 horse johnson burped then just shut down tried to restart but to no avail. it has always ran fine. Now i am getting no spark at either cylinder. opened the control box up and cut the kill switch wire pulled its ground off but still no spark. Ordered new kill switch because other one rigged on control box to keep button pushed in. I read all the other post question about spark but still confused can any one help need to know process of elimination it's Grandmas boat and she has to have it running 