Thanks Dan I have  a replacement AFM I will try tomorrow 

Dennis Jowell
Scotch Hollow Farm
Newbury, Vermont 

> On Aug 27, 2017, at 4:40 PM, Dan N <dn92610@gmail.com> wrote:
> 
> so it's not altitude related...
> 
> besides what I suggested to do/check ... I'd think that the carbon tracks on the AFM were worn at the 3K/3.5K rpm spot (that's where the contact sits most of the time) ... if it's the case then you will need and a rebuilt AFM or have yours rebuilt... unless you want to do it yourself...