UPDATE:
Started by pulling the right access cover off and visually inspected the signal generator - everything looked good and connections were tight.
So I checked resistances in the signal generator (all fine).  Then checked for continuity in the wires between the ignitor unit and the coil on the "no spark" side (all good).  I was about to condem the ignitor unit, but then I thought I'd better re-trace my steps (what are the chances of an ignitor failing because of the bike falling over).  I decided to take a closer look at the signal generator eventhough it looked fine.  I used a wrench to turn the crank by hand so that I could check the gap between the rotor and the pickups... sure enough the left side had about 3 times the clearance of the right side.  I loosened the left pickup, pushed it in towards the rotor as much as possible and tightened it back down (at this point it was approximately the same clearance as the right side). ... then put the plugs back in, reconnected everything, crossed my fingers and hit the start button... vrrrrrooommmm.... started right up and runs smooth.  I was very happy...  didn't need to buy any new parts....    





OK... here's the situation.......
I came back home after running a few arrands and found my bike on its side.  A strong wind gust blew it over.   :x    Yes, I was really pissed.  I picked it up and tried to start it.  BOOM!!!!!!!!!  - Holy crap, did someone just shoot a shotgun right beside my head.... Oh no, it was just my bike backfiring like nothing I've ever heard before.  Anyway, tried it several times and it backfired several times... Ok, enough of that or someone is going to call the cops.  I removed both spark plugs and  checked for spark.  There is only spark on the right one.  I switched the spark plugs to rule out a bad plug... yep, left plug sparked on right side - OK, plugs are both good and still no spark on the left side.  I removed the left side coil and checked resistance in the primary and secondary windings - both within spec.  Where should I be looking next???  :dunno:

Same problem with mine. I didn't think to change the spark plugs to the other side. But as soon as new plugs were installed it started right up. If you have a couple of new plugs laying around you might try that even though it seems  one side is getting good spark.  

Derek

Did it fall on the right side ... if so your crank trigger is dead ... open that round thing on the right ... see if the advalcer or the pick up points are bad ... even if visibly not bad ... they can be bad ...
Cool.
Srinath.

Yeah, it did fall on the right side (only physical damage was the end cap on the handlebar).  I'm going to test the signal generator tomorrow.  I'll let you know how it checks out.

Wooooohhoooo... fixed        :mrgreen:

Good job!