Just recently did a top end job on my WR450. When I put it away for winter, it was running fine no issue. It had been awhile since it had been opened up to check the valves. I figured it was time to put piston, rings, and timing chain in it.
After I got it all back together it wouldn't start. No compression..... Zero. So I checked the valve clearance. The intake valve on the exhaust size had no gap. I take it apart clean it, put it all back together, didn't change ANYTHING, now it has .005" gap. Perfect, right in the middle tolerance! Retest compression 120lbs with the head cover off. Great i'm thinking, except now something isn't right with the decompression system. It will stall the starter with a brand new battery. Try and kickstart it with your foot and it'll about break it. Had to drag start it to get it running. Idles great no issues. Engine rolls over freely with no bindage. Rode it two miles, no issues. Tried to restart it with E-start hot, still stalls the starter. I played with the cam on the decompression system. It seems to return to home position with the spring and no issues. It even moves the little "button" that pushes on the valve bucket.
Any ideas of what I might be missing???