merc 50 switchbox

[moof]

Hi people <br /><br />I've got a 84 merc 50 (4cyl 2stroke) with some problems. <br />All of a sudden there was an almost total power loss. Took it back home and tore into it and found that some of the wires from the stator and the trigger plate were completely corroded.<br />O.K. , no problem, replace the stator and trigger and all will be well again, right?<br />The first time I started it up in the driveway it sounded great! Took it out to the lake and now the thing won't even start. I'm almost sure that the switch box is fried (from extensive tests done to everything else in my Solec manual).<br />The only problem is that they don't tell me how to test the swithbox. (the $50.00 manual forgot to cover that part) I was hoping someone out here knows what the procedure is. <br />Thanx in advance <br /><br />chris

 

[andy6374]

Re: merc 50 switchbox

I have the same Selco manual you do, but mine is for V6 outboards 65-89'. In mine is says the that switchbox cannot be tested with a regular V/O/A meter. You need a special gaget called a Quicksilver Ignition Analyzer. Same thing goes for the ignition coils, but at least the coils can be partly test with a V/O/A meter.<br /><br />-Andy

 

[moof]

Re: merc 50 switchbox

Thanx for the info andy.<br />I think i'm just going to get a new box and pray.

 

[Laotzu]

Re: merc 50 switchbox

One thing you can do is put a sparkplug gap tester on the plugs. I don't have one, but I ubderstand you can buy one at an autoparts store. It will give some indication of the strength of the spark coming from the coils through the switchbox. To test the switchbox output, you need a multi-tester with a DVA adapter. Should be at about 190 volts at crank rpms. This is what it says for my 50hp, but it's a '91 3 cyl. so the readings might be different but in the ballpark.<br /><br />I'd try some testing before I spent $$$$ on a new switchbox.<br /><br />Jerry