it works and is accurate, after a bit of aggrivation. heres the story: I run a MSD 6 AL box with a factory points distributor. At first I plugged the tach into the tach output in the box and the tach worked fine until 1600 rpm. anything more and it would drop to zero. I then orded a MSD tach adaptor, PN 8910. I spliced it in, leaving the tach wire in the side of the box, which made no difference. same deal at 1600 RPM. I re-read the instructions from MSD about the tach adaptor. The instructions were not very clear. out of pure hope I spliced the tach wire into the white wire, and viola it works fine. after reading the instructions again, thats what your supposed to do, but the diagram really doesn't show that clearly. I tested the tach for accuaracy against the rev limiter. I have it set at 4600, and I brought the revs up slowly and set the limiter off. the tach read between 4500-4700 rpm. good enough for me. I'm happy. I ordered it from OPGI, and waited 2 full months for it to show up after being told it would only be on back order for 3 weeks. :error:
