Originally Posted by Pleiades

to XT660.com - not an ideal reason to post your first thread!

If the light flashes when the engine is turn over on the starter, it usually (but not always) means the main relay is defective.

It can also do this when there is a fault with the crank position sensor, ignition coil or lean angle cut-off switch. If these were at fault though you would expect to see the engine trouble light flashing a code when the ignition is turned on (and not turning over or running). Is there such a fault code flashing?

If there is no fault code flashing with the ignition on, suspect/check the main relay operation and its connections first.