Merc 115 No Start

[Volphin]

This 1983 tower of power left dear ol dad stranded on the lake on Sunday. I got him hauled in and popped the cover. Pulled a few plugs. Let's just say he's getting plenty of fuel? they were wet with gas. I had limited tools with me, but it seems that it has lost spark on all cylinders. Now, I'm not an outboard guy, but I did take some votech classes on them MANY years ago. As I recall it has a switch that when inop causes all cyls to lose spark? a merc switch maybe? Or could the stator have gone defective? Any and all procedures for testing would be great...

Thanks guys

 

[Volphin]

Anyone?

 

[Chris1956]

You are right on both assumptions, plus the ign switch could be bad. The first test is for spark. So remove the spark plugs and crank her with one plug held just off the block and watch for a blue snap of a spark. If no spark, pull both black/yellow wires at the switchboxes. The switchboxes are usually stacked on top on one another. Now recheck for spark. If you have spark, the ign switch is probably bad.

Look for a blue plastic condenser -shaped thing. That will be the mercury switch. Disconnect it. Also disconnect the rectifier wires from the rectifier and insulate them. Now check for spark again. If it has returned, the mercury switch or rectifier is bad.

If still no spark, go on the CDIElectronics web site and ohm out the stator and coils. It is unlikely all six coils are bad, but you may find a coil or two bad.

 

[Volphin]

Thanks Chris! I'll do that and report back once I get back to town. On the road all next week too. grrr.