Originally Posted by Uncle Scotty
....or the low range of the gauge is 10:1
ie it is richer than 10:1 from that point on and it just shows a flat line.
Something is borked though, no doubt.
Ahhh, yeah, sounds to me like Scotty nailed it - my guess is the meter ends at 10:1 and you are going into the nines for AFR. Either way, yeah, you should be leaning it out, once, you get a meter with a better range.