I have a '91 Wildcat 700. Recently, I got it out of the garage, and started it up. Last year, I had a burn down, and had to rebuild it completely, along with having the cylinders dipped. To break it in last year, I put pre-mix in the tank, and ran that for a couple miles, then put it away for the winter. When I got it out this winter, I started it, and it ran fine, (lot's of smoke, but that was expected), then all of a sudden, it died. I restarted it, and ran it a little, but it kept wanting to die. When I shut it down and checked the plugs, they were WHITE!!!! Very lean contidion. What would cause it to all-of a sudden go lean? I checked the needles, and they are clean, no varnish on them, no green [censored], nothing. Clean, The jet holes look clean too... I am confused. I need to sell it too, so I have to get it running. Any ideas or help would be appreciated. I am not a really big sled mechanic, but I can figure things out, so please sombody help.

Fuel pump? You can put a "T" in a line and measure the pressure with a guage. Should see 3-7 pounds. If it's low, it could be the pump itself, or a clogged pulse line(the one going to the crankcase). Good luck
Pete

could be the crankcase seals. Did you check them?

Fuel shut-off valve??

Hopefully it didn't burn down again. I burnt one of my pistons a couple of weaks ago and it sounds just like yours- would run, but barely. Check and clean the carburaters really well: that was my problem anyway.