One last thought... You should be running ND W22ES-U (my preference) or NGK B7ES spark plugs. If you're not, get a set, set the gap to .7 - .8mm, and use a torque wrench set at 18.5 - 20 ft lbs. to install (you really don't want to strip the spark plug hole threads). These plugs are the correct heat range for your '78 KZ650. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
