'98 MXZ 670 died on me in the middle of nowhere.

I took my wife's sled out for a run yesterday - plenty of snow, but very warm day. I stayed on roads that had sled tracks as I know soft snow can be hard on belts. We've only had this sled for a little over a month - needed a new top end right away, which we had done by local shop. Have put on about 140 miles since then. So I'm out running around in the mountains and first, I start smelling rubber burning about 10 miles into my ride. I got to a good turn around point and thinking the belt was giving out, so started easing back towards my starting point about 20 mph. I hadn't gone a quarter mile and I hear a "fwap fwap fwap" from under the hood - so figure belt is giving out. So I continue driving slowly to get back on the main roads where trail was not as soft as this road I was on. But about 30 seconds later, the engine started bogging down - like not getting gas or something and sure enough within about 15 seconds, it died right there. Being rather new to this whole scenario my first thought was "would the belt giving out cause this to happen?". I couldn't see that happening. Belt was slightly fried on the one side but I felt it could've still made it back. So I tried re-starting and nothing. Changed over to new spark plugs and still nothing - won't even fire. So I had no choice but to start hoofing it. Did finally run into some sledders and got towed out. One of the guys back down at parking area said he had one of these machines and was pretty sure it was CDI based on his experience. Normally, the sled starts up by the third pull cold, and within two when warm.

So do I try a new/used CDI? Anything else I could be looking at? Wiring looks intact and sled has only been driven on ungroomed or groomed trails.