NS8B - one cyl runs alone, other doesn't.. err..

Hi everyone, thanks for reading

I have a 8hp nissan 2 stroke, and after having lack of power issues have found a suspect problem. If i take off the spark plug wire on on plug, the motor changes rpm but it still keep running strong, when i take off the spark plug wire from the other one it runs sloppy and then stalls. So i have spark in both and the run but one is off maybe the spark I am thinking, just learning here about outboards ..

Thinks i have tried

1. switching spark plugs
2 switching spark plug boots
3. checking compression - it's the same and within spec


I can see anywhere that there is two coils to swap to check on this unit it seems like one big unit, i also don't think you can change the spark plug leads without replacing the whole thing, does this sound like a ignition coil problem to you ? and do these come as one unit or something ?

Thanks !

Pat

Have you tried reversing plug wires? If so, and the symptom is still the same, you have ruled out ignition. It's a siamese coil integral with the CD module, so if one has fire, both do. In that case, you may need to clean the carb. Even flow is an odd thing, and can masquerade as other problems.