Any advice would be appreciated. I'm going to try to fix this myself. Have read through other advice: test the battery, solenoid, starter, plugs and carbon build-up. But does the buzzing sound indicate an electrical problem ? It's been hard to start since I first took it out this year, and made a buzzing sound before starting. Battery seemed dead over and over. Now, even  with a freshly charged battery (only two years old) it won't even buzz anymore. I'd also like to buy a service manual for this: it's a CBX 250. Somebody said carbon build up, so I took it out on the highway for a nice run - made it even worse. Now it won't start at all. Help guys!