Most MTC batterys have the charging rates on the top of the battery.
Just checked the Haynes manual, and they say if you charge with 4-5 amps, only charge for an hour. They suggest a trickle charger of no more than 1.2 amps, and charging no more than 5 hours.
I think I'd try an hour, with your 2 amp, maybe an hour and a half, and start the bike.
2 amps is enough to cook the battery if you leave it on charge too long.
If you're worried, keep checking the battery to make sure it's not getting hot. On some of the batteries, (With a translucent sidewall) you can also watch for the electrolyte to bubble.