Weak spark, no ignition

[swrupert83]

I've recently been gifted a 50 HP 1985 johnson outboard. my neighbor took it out for its first run of the season and about 5 minutes down the river it just shut off. we pulled one plug and turned the engine with the plug grounded and observed a weak spark that progressively got weaker. we pulled it off his boat and he went down the the marina and brought a new 4 stroke evinrude. so i have this engine i wanna throw on the back of my 15ft chrysler.

Upon removing the controls i found that mice had chewed through the control cables (wires). I went down to the marina and borrowed the shorty cable and observed the same spark issue with no firing.

I'm not too sure how it all works, but i did pick up the selco manual for the engine. is it possible that the mice chewed through the 12vdc and the magneto wires and a little salt water conducted voltage across the two?

Just hoping for any idea of were to start

 

[tashasdaddy]

Re: Weak spark, no ignition

you have a stator, charge coils, pickups, under the flywheel, which generate electricity, and supply power to the power pack, this is not a magneto engine. use the proper tools to test. adjustable spark tester (auto parts store). if you have no spark of either coil/plug, all connections are clean, then i would look toward the power pack. test here http://www.boatpartstore.com/page32.asp

 

[swrupert83]

Re: Weak spark, no ignition

well good to know it doesn't have a magneto, haven't started on this engine yet so I haven't even dove into the manual yet , was just looking for a place to start.

my neighbor bought a new power pack for it, before giving up. same condition. as the engine turns there is a weak spark that gets progressively weaker until you can't see it (on all plugs)

 

[tashasdaddy]

Re: Weak spark, no ignition

get a tester.