Any luck on this? My holligans rpm gauge started acting funny today, but ran and sounded just fine. It then seems to have reset itself. Did you ever come up with a fix? Does anyone have any info on this issue?
For me mine was reading 2,000 rpms low, or off by 2,000 rpms. At idle it would read 0 but sounded and ran fine for 20 miles. Got home and it was back to normal...