After a race this weekend my ski started to sound strange when I cruise in lower speeds and lets off the throttle. Its kind of a scratching sound that you can hear the same time as the bov.

I took it for a spin today with no seats on to locate the sound. At first i didnt hear anything, but after a couple of full speed runs it apeared again. I can only hear it when I go of the throttle. The ski works perfect and does not sound strange at even revs, ONLY when i let off the throttle.

25 hrs on ski.