Just thought I would share this with you all as I recently had problems starting my bike. The battery appeared ok and so I had visions of a fuel blockage, carb / starter motor / spark plug problem. After checking the battery with a multimeter it was showing 11.9V - enough, (I thought), to start the bike. Charged the battery up to 12.6V and lo and behold - started first time. Just shows the effects of what looked like a relatively small drop in battery voltage. Interesting.

So rule number 1 - always check the charge on the battery!

Yeah, the starter can seem to be spinning it over okay, but the starter is loading the battery, dropping the voltage enough to keep the ignition system from firing the plug.
A voltmeter, checking the voltage while the starter is spinning would be helpful.