You brought up A good point about the SK line, I have gotten bit once or twice going for that needel valve. Never drawn blood but I have come home with A red knuckle. When Ed Moorman tested the SK 90 I just had to try one, that sold me on SK. I have had great luck with the PRO series and never had A problem with an OS, even the LA series.
Now then, anyone want to buy some MDS engines cheap????? OK, just fishing!!