So I am having issues late in my rebuild. I have started the bike off of a little gas in a bottle with 2 lines from it but after install of the new exhaust and a couple months of other tedious tasks the starter won't engage. It just hums, so I thought it was bad, I got a new one and same thing just hums. The solenoid clicks when I press the start button but that's it just the click and a slight hum. Lights work etc... Could a bad battery cause this?