1987 Honda NSR 250 MC 16 "snowmobile wont start spark" Questions

snowmobile my engine light is flashing what does this mean the other day i was riding and it sounded and felt sluggish almost like it was missing after finishing the ride i started it the next day and

...wont start. Fuel is present now at the carb. I can't seem to take the spark plug cap off, it just swivells, does it need a special tool? Any ideas? Hi, Covello159 and the usual suspects are: 1. ...