Motorcycle Questions? Ask a Mechanic.
You should jump the starter relay with a remote smith or home made tool to jump the contacts, to make sure the starter and engine spin nice and freely. Then you should make sure you have a good ground to switch side of starter relay and a good positive when when you press the start switch. If not, you need to check the wiring from the starter relay back to the starter switch. The starter switch could be the culprit, unless you have completely bypassed it.
Additional info - The battery should be load tested. At the minimum you should test it with a multi-meter. Voltage with key out of bike would be 12.5 or higher 9 If not recharge battery ) and not fall below 9.5 volts using a multi-meter.