I went riding over the weekend with my 250EX and it ran excellent and I had a blast. I cleaned it all up and drove around for about 30 minutes and then got off of it to mow the yard. I got back on after I was done and shifted through the gears in my yard. I shifted down into third and did a tiny wheelie into a ditch and got out of it and let off and it acted like it was out of gas. I put it on reserve and started it back up and let a little fuel get to the carb and it still acted like it was about to go out of gas.
It idles like it does when you are warming it up a bit before riding but it stays at that sort of unsteady idle. I don't know what it is. The plug had black on its bottom so I took a wire brush and cleaned it off and put it back in and still nothing.
This happened all of a sudden too. Runs great one second and then it just won't even get off the line the next. After I cleaned the plug up a bit and put it back in. I attempted to start it a few times. It started but won't stay running past idle. If you try to rev it, it may get one decent rev in then it will die. The plug had a bit of oil and gas on it when I took it out so I know it is getting fuel.
Could the plug be bad? It is a 2001 and I bought it in October as a used one with only 10 miles on it. It still has the same plug on it and possibly the same one as when it was new.
Thanks for the help.