|
By spit-back I mean a backfire in the inlet tract usually indicating a weak mixture. The weak mixture burns slower than required and is still burning on the exhaust stroke when the inlet valve opens on valve overlap hence the 'pop' in the inlet side. If this is happening then the bike needs servicing so the fuel delivery is correct - tps set, throttle bodies check for balance, mixture set with gas analyser and checks for air leaks on inlet side. If it is running really weak then the valve clearances can also have an effect as tight clearances increase the valve event so inlet opens earlier.
I'm sugesting this as a possibility if it really is nothing mechanical causing the click but I hope you appreciate that nobody has heard the bike so we're all guessing and hope that one of them is right! Have you tried my suggestion about blipping the throttle a bit slower rather than snapping it open?
|