Sounds like the starter relay could be faulty and/or the way it's wired. I replace them with a generic "cube" relay - sold as a fog light or horn relay at your local auto parts. Rewire it so that there's a (fused) direct feed from the battery, as outlined here by Patrick Hayes.
The trick is in the brown wire. It leads from the right handlebar to the relay socket under the side cover at connector 30/51. From there, it is joined by a small brown jumper wire from connector 30/51 over to connector 86. Disconnect the relay from the plastic relay socket. Now look at the receiving side of the relay socket. Each terminal has a slot with a small notch. Reach into this notch with a small jewelers screwdriver. Inside is a little tang on the female spade connector. You need to flatten this tang so that you can pull the wire and spade connector out from the back of the relay socket. We need to do this to swap the position of the two terminals within the relay socket.
Once you have both of the brown wire terminals removed from 30/51 and 86, then cut them apart as close as possible where they both join at the old 30/51 terminal. Now, you have the wire from handlebar with a spade female on it and you have a short two inch wire with a spade female terminal.
Use your screwdriver to bend out and restore the little tang on the back of each female terminal so that it acts as a snap lock when you insert it back into the relay socket. Now, reinsert the two terminals into the connector block BUT swap them so that the harness wire from the handlebar now goes directly into 86 and the short two inch wire goes into 30/51.
Now, manufacture a short red wire. Perhaps 16ga and ten inches long with a ring terminal at the battery end, an in-line automotive fuse spliced into the middle and a straight crimp connector at the business end. Splice this new jumper directly to the two inch brown wire dangling from the 30/51 position and install the ring terminal directly on your battery positive post.
You are all done. Now, the 86 terminal only carries the load of the little relay electromagnet coil. The 30/51 terminal (which gets energized when the relay closes) has a new, fat, short routing directly from the battery, throgh the relay contacts to the starter solenoid. No more CLICK when you hit the starter button, just vrooooooom.
Patrick Hayes
Fremont CA
