Michael Jones wrote:

> I just inherited a 1984 35hp Mercury outboard. Physically it's beautiful
> and appears to have been run very little. As most of you know that can
> be bad as well as good.

> On my second outing with this motor, it did beautifully on about a mile
> and a half run to a bay where I then idled around trolling for about 20
> minutes. Coming out of the bay, the boat idled fine but opening the
> throttle only made it bog down and die.

> After idling all the way back to the ramp (an hour), I checked out a few
> things back home. I had initially suspected a clogged carburetor jet,
> but upon checking the ignition system, I now suspect one of the coils.
> What I found was that the lower cylinder was not firing. Plug checks out
> OK and the plug wire is OK. But when I tested for spark, I'm getting
> none from the coil for that cylinder.

> Any tips from Merc owners or mechanics would be greatly appreciated. I'm
> not rich and would like to replace the coil myself if that's the
> problem. On the other hand, I'd hate to replace the coil only to find
> out that it wasn't the coil at all. I've bought Merc's manual for this
> engine and there's a resistance test that can be done on the coil, but
> the manual warns that the test isn't 100% accurate.

> Any and all suggestions will be very much appreciated. I come from an
> OMC background, and there's a lot about these Mercs that's quite
> different (like venting the fuel tanks).

> Mike Jones
> Louisville,KY

Reverse sparkplugs and test,,,, Reverse the upper and lower coils and
retest. If the problem moves with the plug or coil.... If not, move on
to the charge coil and sensor leads ohm tests. { you need a "good" meter
for these checks...} If these seem good take it to a dealer, it's
probably the power pack. Let him test to be sure.