[urq] Aftermarket boost gauge issues

[Gary Brown]

It's an Autometer boost/vaccuum gauge in the console. It reads 25 in/hg at idle, and 10 in/hg with the motor off. I hooked a mighty vac pump up to check vacuum at the port the gauge is tapped from, and it read 14 in/hg, which I believe is correct.
Are these things adjustable? Do I need a new one or is it just dirty??

   
  Car runs fine otherwise.