Maybe this is a difference between the US and Canadian market bikes, but my bike does have a prime position. It isn't marked, but if you go to the run position, then turn a quarter turn to reserve then try to turn another quarter turn, you will be stopped by a philips head screw on the petcock. Remove this screw and you will be able to turn the additional quarter turn to prime position.
Anyway, like Rob suggested, turn to prime and give the carb bowls time to fill.
I would also carefully check all the vacuum lines and the carb boots for leaks. Even a small leak could cause it to fire up a bit, then die.
Also Pete, as a word of encouragement, I wouldn't be too quick to give up and take it to the shop. You seem to be willing to do a bit of work on it, and in my experience these bikes are pretty reliable on the big things. It's little stuff like vacuum leaks or leaky carb o-rings etc. that screw up. If you have a bit of patience, you can probably sort it out yourself.
Besides, I live in Eastern Ontario like you, and you're not riding anytime soon anyway.
Regards,
Steve