None!
You can however have your OEM re-wound. It's a royal pain in the ass to do it yourself. I have, and won't do it again.
Most GOOD cycle shops can do it for around 125.00 US but the most you will ever get out of it is 45a continuous, and 75 peak.
The best thing to do is convert the bike to LED's, and reduce the running draw to around 5-7amps