I bought my 650 last year and it ran great all season. Over the winter, I stored the bike in a garage and didn't take out the battery. After a few rides this year, it seemed to be working ok, then as I was getting gas after an hour-long ride, the bike didn't start again (no indication of battery). I couldn't push start it, so I towed it to my mechanic and he said the connections were loose, so the battery wasn't getting charged. Fine. The battery was re-charged and worked well again. A week later, I took a ride in the rain and stopped in a parking lot. Again, the bike wouldn't start. This time, the starter solenoid was buzzing, but nothing past that. I tried to push start a few times, but no success. After the rain had stopped, I went and push started the bike to get it home. I was worried about it quitting on the road, so I didn't open the choke all the way.
Now, if I charge the battery, I can get one good start. The bike warms up. Then about the time I would normally push the choke lever in, it starts to idle very low and neither throttle, choke nor idle adjustment will save it. By then, the battery charge is low enough that the solenoid just buzzes again, and I have to recharge the battery. At rest, the battery reads ~12.5V. With electronics ~12.3V. Bike running ~15.2V. After the first start ~11.5V
After much reading online, it sounded like I probably needed a good carb cleaning, so I took it out and cleaned the jets. Everything looked pretty clean. The carb cleaner ran through all the jets, and I re-assembled. The same thing is now happening. I can start, it runs for about a minute, then idles low and quits.
1. Do I need a new battery? I just wanted to check before I go buy a new one and find out that I didn't need it ...
2. What else should I check as far as the mechanical part goes? The air filter looks good, plugs look ok. I'm not sure what the next step is.
The whole point of me trying to do it myself is that I'd rather learn myself what's going on and be able to fix it in the future than having to tow it to get repaired blindly.