It just won't. Plenty of spark, tank's full, air is there, but nothing. Anybody else ever had this problem?

 

Is the choke working? How cold is it?
Youve pulled the plug out, hooked it up, cranked the motor...and saw the spark?
Check compression next.
If things look in spec, and you have spark, it just might be too lean for the temperatures.
You can try covering the intake with a mitten or rag, and try to reduce the air by about 3/4..this will make it very rich, and should help to make it fire in the cold.

 

its in a heated shop. I was ridng it last week, ran fine no problems. There was lots of spark when i pulled the plug, hooked it up and cranked to motor. And now the thing won't start. Everything works but nothing makes sense. I'll check the compression but i dought thats it, i don't have any engine mods so theres no reason for there to be an internal engine problem. How about the fuel filter could that posibly plugged?

 

Open the drain on the float bowl...if gas comes out, we can assume nothing is plugged to the carb.