is 100 RPM low... critical? might depend on the airplane, if you are the
only one that flies it, and knows it.. or post a placard..

does reading 100RPM low at all ranges, effect the total time accrued? most
likely.. by miniscule amounts..

make the new tac read the same total hours as the old?? why..

just make a log book entry of total time when old tac was removed, and tac
reading on new tac when installed, each maint log after that will carry the
correct total time forward.

What does your mechanic say?

BT

"Ben Smith" wrote in message
...
Hello -

Our mechanic verified my hunch that our tachometer is reading 100rpm low.
(At all ranges). Should the tach be repaired, or replaced? (Or left
alone?) Also, if I get a new one, is there a way to have the indicated
hours made the same as the existing one?

TIA

--
Ben
C-172 - N13258 @ 87Y