Look right at the beginning; it seems like its not just the tach but engine speed actually is affected too
It does NOT jump around while riding

EDIT: problem is neutral switch. it was cutting out with kickstand down only.
F4i tachometer jumping - YouTube

 

It looks more like your just reving the **** out of it to me.

 

haha, I know in the middle of the vid it looks like, but watch right at the beginning and at the last half of the vid.

 

I was waiting for it to POP!

 

great, but that doesnt add anything to this thread nor help in any way. Glad to know you would like to see a member's motorcycle blow up

 

I never said that, I don't like to see any motorcycle "blow up" especially a bike owned by another cbrf member.

Anyway sorry for not helping, If you havn't already start by the checking all the connection's to the tacho are secure and give them a clean up.

 

no ideas guys? Any idea where the tach gets its reading?