Trigger fires multi times

[dave 416]

HI all I have a 1989 100hp mariner thats not running right I indexed the fly wheel and have found that the two top cylinders are being fired multi times such as when the other cyl are at top dead centre I have replaced the trigger and no change I think the ignition coils get over loaded and cause the motor to stall any help would be appreciated thx

 

[dave 416]

Re: Trigger fires multi times

I should add that I used a timing light to confirm that the cyl was firing more than once per revolution it has a new stator and switch box

 

[Texasmark]

Re: Trigger fires multi times

My service manual shows 3 pickup coils for both the 3 and 4 cyl engines and one magnet. The coils are interconnected electrically in an intricate fashion and it can get confusing. In reading the SM troubleshooting guide, mention is made of ensuring that each of the CDI's are adequately grounded to the mounting plate and that the plate is adequately grounded to either the block, or the negative battery lead.....which is usually connected to the block, or to the starter with a jumper to the block.

Having a bad ground makes sense with the way they are interconnected and very well may be your problem. Makes perfect sense to me.

So I think you need to remove the modules and any interconnect wiring and clean up any metal that completes the ground loop.....take it apart, don't just shine up the outside.

Mark