only 2 cylinder work on a 4 cylinder outboard

[laopi]

Hi,

I had a 1996 40 hp mercury, 2 stroke, 4 cylinder, which is hard to start, I found when the engine is in idle, I disconnect the cylinder 3 & 4, theres no change, I bought 4 new plugs, same as before, and when I took off the all plugs, 3 & 4 are wet, looks like no firing, however, when I test the 3 & 4 I can see weak spark,

Any suggestion about the issue?

Thanks.

peter

 

[Iceman66]

Re: only 2 cylinder work on a 4 cylinder outboard

Possible bad switch-box,but look at this:

CDI Electronics Practical Outboard Ignition Troubleshooting

 

[laopi]

Re: only 2 cylinder work on a 4 cylinder outboard

thanks， that really help