Is the primer actually getting fuel into the intake? Also I am not sure on the year, is there a choke?
After trying. are the plugs wet?If not, try this...
Put a small amount of gas straight into your carb(s), and try to start it, if it starts good, then your primer is shot. (I dont reccomend ever using a starting fluid)

If they plugs are wet, are they gapped to spec? and does the spark appear strong?My 500 spark will actually jump 1/2"or more easily... (found out the hard way...ouch).I don't really know much about the rotary timing, or R.A.V.E. setups (if that would even apply to starting), so I'll leave that for the guys here that know there stuff!

Good Luck!

ADD: Sorry also forgot to mention there is an excellent HOW TO & Tips thread here at:


http://www.snowmobileforum.com/engine-drivetrain/7254-sled-how-tos-here.html

 

I have the 1997 Formula 500, so maybe I can help. Usually even with a slow pull you should be getting good spark. It might have a weak stator. Also like the previous guy said, check your primer and make sure you see fuel flowing through the lines.
There is no choke on these sleds, just a primer, which usually makes them fire up quicker than a choke.
Yes you should be able to add electric start, I dont know if it needs a different crank. But you would have to buy a fly wheel for the starter and the starter. Your lookin at a couple hundred bucks. Y0our best bet is to find a donor sled.