Only way to check current is with a load.
A healthy battery will be close to 13 volts with no load. If it's below 12.8 volts it may be on its way out or need to be charged.
Once again, electrical fault finding via a forum is very difficult. Too many questions to ask to try to find the fault.
Always start with the basics:
Battery - if the battery is good then it could be
Fuses - if the fuses are good (tested using a multimeter, not visual) then
Bad connection - check the heavy current carrying cables first. battery to fuse box, battery to starter, all the grounds
If none of these solve the problem, then it's down to eliminating possible causes one by one.
Rockets are known to have weak ignitions
If nothing helps, buy a Yamaha Venture