Riding today, I knew my engine had a slight tick but I thought nothing of it. Fresh oil, checked over everything, everything routine right, well I rode it a few hours today and the engine completely grenades on me, explodes and oil goes everywhere. Now my friends bike did this but it wasn't smoking and didn't explode but oil went everywhere and all he needed was a new valve cover. What could've been the cause of this? Well here's what lead up to it. Riding trails with my little bro, went down a hill, turned and started on a trail back up the hill, went to shift into second but missed and hit neutral and I looked down and oil was everywhere and smoke everywhere so I shut it off immediately. Little bro says on the downhill, 10 seconds earlier, no more, he saw white smoke coming from my exhaust for a good 3 seconds and it stopped and he didn't see it again. Then all of a sudden when I shifted into neutral by accident I looked down and there's a huge smokey oil mess. Shut it off right there. So idk if its as from me shifting into neutral or if it ran for a few seconds before I shut it off. Either way, what do yall think could be the problem? Valve cover, piston ring, crankshaft, etc. just hoping and crossing my fingers that it isn't a rebuild because I don't have the money for a thumper rebuild. If that's the case, I may sell it saying it needs a new engine. This really sucks.