sp5 wont spark

hey guys having a problem with the duke
as it says, turns over fine but no spark, i did notice that when i operate the engine , off/run button at the throttle back and forth the plug will spark but when the starter button is pressed and the motor turns over but there is no spark, checked the crank pick ups on the ohms meter and all is fine with them
any help would be great as the weather is here for some 888 fun