Last weekend the 4 wheel drive on my bike just suddenly quit working. No noise or obvious problems - always kept up on the maintance for it....Any ideas on a likely culprit? Was riding across some kind of wet plowed ground in a field and noticed I was sinking a little bit. I looked a little closer and noticed the front end had quit pulling. By the way, put in the call to Honda and they said probably a $1000 job if it's the clutch or something along those lines. Any thoughts/experience appreciated. (Bike is a '97 Foreman)