[94ZR580]

Did you look down the plug hole of the gray plug? Gray is usually melted aluminum, so like what was said above, you need to do a compression test to help tell you if that piston melted.

 

[94ZR580]

You're going to want to look to the rubber flange that connects the throttle body to the cylinder. They tend to develop cracks under the clamp and that leads to an air leak, which results in a lean condition and a melted piston. That is one of the more common causes of lean burn downs on the EFI machines. A pressure test will tell you if the cranks seals are in good shape.