I agree, that with the engine in good tune it should fire off in 2-3 seconds of starter operation .
To get back to the starter, there is a test to see if the starter is using too much power .
Fully charge the battery remove the ignition leads from the spark plugs .
Put old plugs in the leads an place them on the cylinder .
Or, if you have run the carbs dry, so it doesn't start .
Put a voltmeter on the battery .
Operate the starter for 45 seconds to get the top charge off of the battery .
Then operate the starter and see what battery voltage you have, it shouldn't go below around 10.5 volts .
If it does, the starter is probably ' dry ' on lubrication .
With the electronic ignition, it doesn't work well if the starter is using too much power .
I've taken apart, cleaned and lubricated all the Bosch starters on my R65's and Guzzi, same starter on the Guzzi, just a different number of teeth on the gear that contacts the flywheel .
I had trouble starting my '81 R65 about 13 years ago, when the temp dropped below 55 F, 13 C .
I had multiple issues, dry starter (9.5 volts when doing the test above ) and a weak ignition coil, second generation OEM dual output coil, the red and black version and they had just introduced 10% ethanol in the fuel supply .