Hmmm......no responses.

I do see there have been over 100 views, so I'll go ahead and post what I've done since my last post that seem to help; maybe it will help someone reading this.

Since I couldn't find anything wrong with the internal parts of the Viper, I thought perhaps it wasn't getting quite enough pressure to ensure the piston in the manifold wouldn't stick in the spin out position. I checked the hose and found one of the swivels was leaking. I replaced the swivels and that seemed to solve the problem. However, the Viper still seemed just a little sluggish. I checked the pressure, and sure enough it was a little low; about 21lbs (should be 25-30lbs). I suspect with the leaky swivel, it was a little lower. I removed the Automatic Flow Regulator in the Wall Quick Connect as suggested in the owner's manual, but this raised the pressure to about 34lbs. I'm not sure how "automatic" the Flow Regulator is since it's just a star shaped piece of plastic that just seems to restrict flow by a set amount. I modified it by cutting off some of the points on the star shape piece and was able to raise the pressure at the cleaner to about 28lbs. Now my Viper seems to be operating normally again.

I hope this thread helps someone out there.