I have a 2004 XT660R. It will only start if it has been on a charger for half an hour or with a boost pack.

Even with a brand new quality battery.

It needs a really high battery voltage to get a spark. The starter motor spins fine and fast and the coil is getting power to the primary, but it will not spark unless the battery voltage is maxed out.

If I leave the igntion on for a couple of minutes so the voltage drops, the coil won't spark. Even though it's got more than 12v.

Tried a new coil, new main relay, new reg/rect. None make a difference. The starter turns no faster on on the boost pack than with the stand alone new battery.

Could it be the ECU ? I assume it controls the coil.

I'm not sure how battery voltage could affect the triggering of the coil. Especially with a new battery.

Has anyone ever seen this before ??

Thanks in advance.

Ted