Hi RCLT40,

It may be that the clunk has moved to the front of the tank following storage or a rapid deceleration. Hold model vertical by prop and shake until you hear the clunk rattle freely at the back of the tank, then shake the model.

If this doesn't help you need to check the settings of the high and low speed needles and or check for air leaks. This is a process of elimination procedure and I suggest you have one of the more experienced flyers advise you as it is much easier to show that describe.

Godd Luck,

Colin