There is an old post on here regarding MC16 CDI repairs. This seems to be a common problem with this model. When my bike gets up to temperature it was randomly dropping a cylinder. Swapping the CDIs the symptom swapped cylinders so i thought o.k. lets have a look inside. So after cutting the unit open and carefully picking out the rubber sealant the circuit board is revealed. Nothing obvious to see, no scorching from burnt out components. At first glance all the joints looked good. I resoldered a couple of joints behind the plugs as this is where the 12v comes in. Tested the unit and its working perfectly. So the moral of the story is dont be scared to have a look at it. And as someone hes previously stated just because the solder joints look o.k. doesnt mean they are. A bit of careful soldering could solve your problems. Regards, Andy.