cd unit

[scotssandy]

help please, i have a 4cyl 50hp mercury , is only firing on 2cyl at the moment have eliminated a few problems , have determined that the plugs,leads,coils are all fine, this leaves the cd unit or the stator , stator seems to be putting our power and charges the battery ok, but still only firing on 2 cyl could this be caused by the cd unit only half working ??????

[boats.net]

The CDI unit, trigger coils or stator could cause that. Testing ignition components as per service manual is the only way to tell which one is faulty.