Jack, I doubt that this particular example has done more than 10 hours use, because it has all the original grease packings and stickers, and when I pulled the head it had very little carbon deposits inside and around the cylinder bore/head/exhaust, so I think we can rule out a worn clutch, and even though this is a two stroke, I have adjusted the throttle cable so I can have it at a just above idle rpm and it will putt along very nicely. Any extra info would be appreciated. Thx