I have a '82 Suzuki gs650e that I haven't had running for a while. I put a new battery in it and it fired up. Had it running for 15 minutes then it died. Now it will barely crank over... it's not the battery since it is new. Lights and indicators are strong. Any ideas? Starter? Tried to start it later and it cranked over then slowly wouldn't crank.

Sounds like a loose connection between battery and starter. I would start checking the wiring, you said it sat for a while, it doesn't take much for (wildlife) to find a new home!