72 115hp ignition problem

[birdnbuck]

This motor set for a while so I replaced switchbox and rectifier. I had it running great. Ran it just three days ago. Went out to start it today and no fire to plugs but it fires when you are turning the ingniton off. Any ideas.

 

[tashasdaddy]

Re: 72 115hp ignition problem

i open a 1971 1350 control box once. the insulation, was gone, sound like you have the same problem, wires or the ignition switch shorting out. if the kill is grounded it will not fire.

 

[tashasdaddy]

Re: 72 115hp ignition problem

youi're probably in need of a external and internal wiring harness, here's a wiring diagram

http://www.maxrules.com/oldmercs/Wiring/1966ona/32.jpg

 

[emckelvy]

Re: 72 115hp ignition problem

Do the ign checks and bet you money you'll find the distributor trigger is bad.

Here's an excellent troubleshooting thread and if you scroll down you'll find the Clams Canino CDI Ign Check instructions:

http://www.iboats.com/bbboard/bbBoard.cgi?a=viewthread;fid=29;gtid=933928

 

[timmathis]

Re: 72 115hp ignition problem

Also could be a bad key switch. That can cause that motor to fire when you turn it on or off only.
See the troubleshooting guide at
www. outboardparts.com
Click on mercury then troubleshooting on merc batt cd ignitions. Tim

 

[tashasdaddy]

Re: 72 115hp ignition problem

Tim and Clams know more about mercs, than i'll ever know. but i like my omc's.