1998 skidoo formula z 583 rave

I have a 98 skidoo formula z with a 583 rotax motor in it and I am having problems with it not wanting to start when it is cold out and the first time I had it going this year it ran fine until it started to make a poping noise and it died it has had the top end rebuilt twice and the carbs cleaned it has 130 compression in the one side and 120 in the other side is there something I should look for that would cause it to just die and not want to restart

1998 skidoo formula z 583 rave