That's why I won't ride the dunes, if you're not air tight gonna be sucking in some sand.
I never had a bike blow up, bikes usually become noticably hard to start when they need a new top end.
The only bike that ever blew up of mine but I wasn't riding it was a 1970 Honda SL125S (4 Stroke). I wouldn't really count that though because that bike sat in the woods for years before I got it and we tried to get it running. It was never running right and when my dad thought he finally had the points adjusted right (which were actually ones we had laying around from an ATC 90), it locked up in 3rd gear. Never took it apart though or did anything with it. So being that it was sitting out in the woods for years before it was given to me I can't count that as an honest bike blow up, was amazing the bike was running at all.