Bike was stored in an unheated shed unfortunately this year, never again. It started doing this late last year but I could get it going with a little cranking. On a cold start, full choke, it started but ran for 5-10 seconds and stalled out. It doesn't rev up like it used to last year. Tried turning it over some, it backfired and that was about it. I did put fuel stabilizer in it prior to storage, I did have it out for a short run, seemed to work o.k. Then it sat for a week or so, now this. Took the plugs out yesterday and tried grounding them, the spark looked yellow, orange color, not bright. Getting new plugs in a few minutes.