What # power pack would I need for a 1977 Johnson 70hp seahorse?

Question

I have a 1977 70 hp Seahorse outboard motor and the bottom coil is not firing I changed to a new coil and still no fire. I think I need a new powerpack. I need to know how to find one to search for. Thanks Chris

Answer 1

Part #113-1726 from CDI electronics. $84.61.

Go to this site, http://www.marineengine.com/  click on Johnson, then click on, Search by Year / Horsepower / Model for 1978 - 2007 model common parts, then click on the CDI catalog. Then again click on the Johnson section, and the list comes up. Yours will be on the 7th page.

Answer 2

part #0581713

sometimes you can find 'em on ebay.   I'd stay away from used parts, they require specialized equipment for testing.

Couple on-line vendors I like are http://iboats.com and http://www.ishopmarine.com

Powerpack is the most likely suspect, but you haven't ruled out the timer base.

Measure the timer base resistance from black/white wire to white/black wires, you should get 10 - 20 ohms.  Any other result, replace the timer base.

If you have a multimeter with a Direct Voltage Adapter (DVA), measure the DVA output from the timer base from the black/white to the white/black wires (while connected to the powerpack), at cranking speed.  You need at least 0.5V

Check the DVA output from the powerpack on the orange wire to your bad cylinder (while connected to the coil), if it's less than 150V, that confirms bad powerpack.

Honest with ya, I'd confirm the new coil is operating by hooking it to a known good cylinder -- I just don't like buying parts without knowing for sure.

If you don't have a DVA, I'd replace the powerpack first -- way easier, and there's worse things than having a spare powerpack on hand.

For future reference, you can just swap coils between cylinders to rule out the coil, before buying a new one.