I never charge a motorcycle battery at more than 1 amp. You can safely leave it on a 1 amp charger for 24 hours. As someone said, not all batteries work right with those battery maintainers. But if the battery is charged, or has been on the charger long enough, and still won't start the bike, there is a problem. If you can jumpstart the bike, then the battery is bad.
"I refuse to give up the thrill of living for the relative safety of existing" Nick Ienatsch
"Life is not a race. Don't treat it as such. If you don't believe me, just have a look at the finish line"