Mercury 25 no spark

[Aaronveve21]

I have a mercury 25 hp I have no spark,checked kill switch it is good with no ground up to the Cdi box. I don't know how to check the Cdi box. I disconnected the rectifier still no spark, I believe it is either the trigger or the Cdi box. I was motoring and it just died with no spark at either spark plug. I could use some help here gentlemen thanks.

 

[orbanp]

Re: Mercury 25 no spark

Hi Aaronveve21,

Welcome to iboats!

You really should post the year and model number of your motor, without that you would only get generic help!

As for to get started, here is link to troubleshooting marine CDI boxes: Technical Support | CDI Electronics

Good luck, Peter

 

[MH Hawker]

Re: Mercury 25 no spark

Had the same thing happen last year, got it home and ran the ohm tests and it turned out to be the CDI box.

 

[Aaronveve21]

Re: Mercury 25 no spark

well I didn't give the most important info the motor is a 1987 Mercury 25hp engine.

 

[orbanp]

Re: Mercury 25 no spark

Here is a link to the troubleshooting information on your engine, on page 76, if I am correct:
ISSUU - CDI Electronics Practical Outboard Ignition Troubleshooting by CDI Electronics

Good luck, Peter