i would replace the ball joints top and bottom and maybe the whole a arms. I had the same thing happen to me on a yamaha warrior about 2 years ago. I was hauling butt up a hill in 3rd gear and all of a sudden i was flying through the air! Luckily i had my helmet on so when i landed on my head all it did was kinda jam my neck lol. be sure to check your spindle too and make sure the hole that the ball joint sits in isnt wore out.
1995 Blaster. Bored .040" , midrange ported, head rechambered, pro series reeds, FMF fatty/Dg silencer, lightened flywheel, +4 timing, Hydro brakes, Lonestar +2 a-arms, Works dual rate G-series shocks, +2 swingarm,. More to come