Small Engines (Lawn Mowers, etc.): Snowmobile C.D.I. problem?, yamaha 540, personal sled

Question
Sir,
First I like to thank you and people like you for helping people like me for no
gain other than just being helpful.
I have a 1990 yamaha 540 xlv snowmobile. Last winter is when I started having a
problem. The engine would start and run for 25 to 30 seconds, die and wouldn't
start until the engine got cold (the next day). I thought I had a carb. problem
and left it until this year. When I started it this year, the same thing, only this
time it started twice. Now I have no spark at all. I replaced the ignition coil
and still no spark. The question I have, is there supposed to be voltage coming
from the orange wire that comes from the C.D.I. to the coil? Or are there any voltages
from the coils inside the motor to the C.D.I.?
 I guess what I'm what asking, is there any way to check the C.D.I. and are
they more likely to go out than the coils inside the motor?  

Answer
Have you replaced the spark plug?  Are you grounding the spark plug when you check for spark?

CDI can be challenging to troubleshoot.  I have some check in spec (resistance) but would not work when installed...really weird problem.  Replaced the module and never had another problem.

The coils inside the engine rarely fail.  Unfortunately we do not service snowmobiles and have no reference material on your machine.  Have you checked Ebay for Yamaha factory repair manuals for you sled?
First thing I would do is replace the spark plug.  I have fouled many spark plugs in my personal sled and never go out with a couple of spare spark plugs.
Eric