Timing Cover Question

[jfmerk]

I recently picked up a NOS timing cover and noticed there was a difference from my original that came off the bike. The original has some type of firm rubber bonded to the inside surface of the timing cover. The NOS cover does not have this. Is it anything I need to be concerned with? Does this act as some time of insulator?

Thanks for the help!

[jfmerk]

Typo:

Sorry, "type" of insulator, not "time".

I recently picked up a NOS timing cover and noticed there was a difference from my original that came off the bike. The original has some type of firm rubber bonded to the inside surface of the timing cover. The NOS cover does not have this. Is it anything I need to be concerned with? Does this act as some time of insulator?

Thanks for the help!

[bikerphil]

My 79F had that type of insulated cover until the bike fell over and cracked it . I think it was put there to lessen the ringing sound that is sometimes given off by the timing plate wheel. All the replacements I've run across didn't have that noise damper.