My People 150 did that once. I believe it was the fuse that controls the ignition may have slipped a little in the holder causing the spark plug to lose it's spark. On the road (and I had been pushing it hard) I replaced the fuse with the spare, and it started back up. I could not see anything worng with the fuse, but left the new one in till it got me home. Later, I tried switching that old fuse with the new one, and the 150 started and ran fine. That's what led me to believe that the first fuse might have vibrated a nd slid a bit in the fuse holder. This was about 2-3 years ago, and that same fuse it fine.