Power Pack for V-4 72 Johnson 100

[jjpruett]

I have had a 1972 100HP Johnson (#100 ESL 72R) for a number of years. Before I had the boat, my father had it and around 1999 or 2000, the power pack was replaced. I have used it during the summers since around 2001 and have had to replace several ignition parts over the years such as the rotor and rotor assembly, the sensor assembly and the stator assembly. However, the powerpack has not been replaced since around 1999. Two summers ago, I began to have problems getting the engine to start and it seemed that there was no fire from the plugs. I had "tapped" the power pack a few times and then the engine would fire and run fine for several weeks. Then it would not fire again. This happened for all of the summer of 2008 but in 2009, I could not get the motor to fire at all. At that time, my repair shop said it would be $500.00 or more to look at the motor and replace the power pack if needed. Looks like I can do better to order on line and the power pack replacement is pretty simple. QUESTION: is there a sure way to check to see if the power pack is truely the problem?

[linknsync]

power pack

if you have a manual that's a good way to check,you can't go wrong with a manual. good luck, linknsync.

[boats.net]

You would need a peak reading voltmeter to test ignition components.