My 225 yamaha has intermittent spark to #5cylinder I have swapped coils wih no change . With the engine running I disconnected the coil positive bullit connector and slowly re-plugged it and get spark between the connector (not actually touching connectors) but loose spark as soon as the connecters make contact. The cylinder will fire when the engine is cold but loses spark after the engine warms up for a few minutes .I am leaning towards replaceing the CDI UNIT but without knowing for sure, its a rather large investment for a spare part (electrical parts are NO RETURN).If anyone has some expierience with this problem I would could you please reply .THANKS T Dickson