We were out at Glamis this weekend enjoying a last dune blitz before it gets Chernobyl hot. Everything was fine until we found ourselves at the infamous four o'clock drags. I took a 2/3 speed pass...fourth gear pinned. Everything was fine. I get ready for pass number two. This time I get a bit more serious, and dip in to fifth gear. At the end of the run, I stab a few quick downshifts while braking to make the turn-around. On the way back to the starting line, I notice the bike is missing all of a sudden. I decide it might be a good idea to let it cool down a bit, So I shut it off. about 10 minutes later, I kick it, she starts right up, and I make my third pass. This pass was supposed to be nothing but evil intent. Nope. I hammered it, and did get all the way to fifth gear pinned, but it is obvious that it's missing badly and not very fast. As I go to make the turn around again, the bike abruptly dies. It isn't siezed, and is getting gas, so I know it's spark. I park it.
After about an hour, we loaded it in the truck and hauled it back to camp. On a whim, I pulled the plug, which was dry as a bone but charcoal gray in color. I popped in a new plug, and she fires right up! I took it for a ride, and it rides fine. By this time, it is getting dark, so I parked it for the night. I left the next morning, so I haven't done anything with it since.
Do you guys think I simply fouled a plug, ir do you think that perhaps the ignition (original on this '87) may be getting ready to go? I can only sirmise that if it is the ignition, it is related to temperature...when resistances go up. Any thoughts here would be appreciated.