72 Merc 115, Coil or Power pack ?

[liebe722000]

I pulled the coil wire out from the distrubitor cap and held it near metal, no spark. One guy said power pack, but it could allso be coil. When my wife turned the engine to check spark, i removed all plug wires before. Did i check it right ? Allso, what does one check when one pulls the coil wire out from coil and hold it next to metal ? I thought i was checking dist cap ? And how can you tell if fuel pumps are working ? Thanks Guys. Mark

 

[AMD Rules]

Re: 72 Merc 115, Coil or Power pack ?

The electricals on the older Mercs are sensitive. Its best to follow documented diagnostic procedures to avoid creating additional problems.

Given the age of the motor, a service manual is a wise investment. You'll get some excellent advice on these forums, but that should be complimented by a good manual. The Mercury part number for the manual is C-90-68647.

What is the primary symptom you are trying to resolve...no spark, no power, not running, running rough, etc?

Here's a good video that shows how to test for a strong spark:

Compression and spark check (windows media file)

 

[Scaaty]

Re: 72 Merc 115, Coil or Power pack ?

MANUAL! Ya start yanking wires looking for spark, end up frying the switchbox or who knows, millions of other little old Merc idiosyncrasies...probably a busted trigger anyway to begin with..

 

[liebe722000]

Re: 72 Merc 115, Coil or Power pack ?

runs on water for awhile then dies. Hard to start, no power.

 

[Clams Canino]

Re: 72 Merc 115, Coil or Power pack ?

Forget the coil. The problem is more likely the switchbox or the trigger. Do "the switchbox test" for elimination.

-W (and get a manual)

 

[liebe722000]

Re: 72 Merc 115, Coil or Power pack ?

How do i do that. Also did compression test and got 100 on all 6. Is it time to sell ??