Motorcycle Repair: engine gos dead when you throttle down, land vehicles, fuel additive

Question
whenever i let off the throttle the engine go's
dead.but not all the time.has new plugs and one
tank of a product called seafoam a type of fuel
cleaner. 2001 kawasaki vulkcan classic 1500e  

Answer
Hi Chuck.
 Never heard of any product called "Seafoam", so I do not recommend using it.

 From the name, My guess is that it is designed for fuel for boats which have a noticably different formula from land vehicles.

 That additive may be most of the cause of your troubles.  But also check your idle setting.  It could be a little low.  Make sure that it is set to the recommended speed as per the repair manual.  You should also check the carb synch as well as the valves and timing.  Are they due or overdue for adjustment?

 If you must use a fuel additive, then use one specific to land vehicles.  STP and it's like are the best choices.  The ones with jet fuel or made from jet fuel are also exceptional.

Start with that and let me know what happens.

Good luck.
FALCON