I had something strange happen over the weekend. I was out in the desert doing a big loop. About 75 miles into it my WR400 started making a very bad knocking noise from inside the engine. I stopped to check it out. It wasn't boiling over and there was plenty of oil in it. It sounded like one of the bearings in the connecting rod had blown out, knocking each time the piston went up and down. I started and stopped the bike a few times. I decided to try to limp it to the nearest road, started it up and while I was turning around, the knocking totally cleared up. Since I still had 25 miles to go, I went for it. The bike ran just how it should!?! What was that?!! I haven't been able to check into it yet. I'm going to drain the oil and see if there are metal pieces in it. Any comments?