Mercury 50hp Switchbox

Joined
Jun 20, 2007
Messages
9
I figured out what I thought was a spark plug fouling problem. The motor would run good for a little while and then act like it fouled out a plug. Today I hooked my timing light up to all 4 cylinders and found that cylinder #1 was dead. I got acouple small flickers out of the timing light but that was it. My theory was that the switch box was slowly going out on me until it totally quit. I called my local Mercury dealer to ask some questions about it. He told me to switch the hot wire on the coil from the bad cylinder to another coil. I did so and my problem followed to that coil. This tells me that all the coils are good. The dealer told me it could either be the switch box or something else which I can't remember what he said. Basically he was telling me it's time to bring it in. I'm not giving up without a fight.:mad: Any thoughts on whether its the switch box or something else? Any other ways to test parts before spending acouple hundred dollars. Thanks
 

DuckOfDeath

Seaman
Joined
Jun 18, 2006
Messages
70
Re: Mercury 50hp Switchbox

I have an '88 Classic Fifty with the same problem. Top cylinder only works intermittently. I've also ruled out the coil, plug, and plug wire. From what I've read here, it's likely the switchbox but I don't think I can troubleshoot further without a DVA meter. I'm saving up for a new switchbox.
 
Joined
Jun 20, 2007
Messages
9
Re: Mercury 50hp Switchbox

I remember what the other thing that could possibly be wrong is. It is the trigger. What is a trigger and where is it?
 
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