25 hp running on 1 cylinder

[Corvairdave]

I have a '97 25hp Merc outboard that is running only on 1 cylinder. I have been troubleshooting and have worked it back to no signal coming from the CD box on the green wire going to the coil for the lower cylinder. Are there specs for the CD box and for the units feeding the box? Any help would be great. I am going to try a CD Box from a 2003 20hp Merc Jet. Cheers, Dave

 

[Corvairdave]

I have a '97 25hp Merc outboard that is running only on 1 cylinder. I have been troubleshooting and have worked it back to no signal coming from the CD box on the green wire going to the coil for the lower cylinder. Are there specs for the CD box and for the units feeding the box? Any help would be great. I am going to try a CD Box from a 2003 20hp Merc Jet. Cheers, Dave

I tried the CD box out of the Jet motor which is the third one I've tried for troubleshooting. My question now is; what is under the flywheel that if sending a signal to only one of the cylinders?

 

[Corvairdave]

I have ruled out plugs, plug leads, coils, CD box and kill switch wire. The 'hot' wire for the top cylinder coil is sending an intermittent signal. I'm running out of ideas.....

 

[flyingscott]

I believe there is only one pick up under the flywheel. Maybe you have a magnet off under the flywheel.

 

[Corvairdave]

My troubleshooting skills need work. On a whim, I tried adjusting the 'mixture' screw. Missing cylinder moved to the bottom one. Turned it all the way in til stall, then backed it out til stall and then a happy place in between. Took it out on the river yesterday, and while it wasn't great, it ran quite smooth on both cylinders. I'm going to order a carb kit and then ultrasonically clean the carb for the spring. Thanks for all the help!