Unfortunately, because you opened the motor, I don't think Medusa will warantee it. However, contact them and see what they say would be my advice...
http://www.medusaproducts.com/motors/028.htm
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S