I also have a 100 HP merc. On mine, the tach "chirps" at low rpm. The
chirping speeds up with the engine rpm, gradually diminishing at about 2000
rpm. It's somewhat annoying. Can the tach be dismantled and lubricated?

--
Denis Roy
D. Roy Woodcraft
www.ideasinwood.com
"Tony Thomas" wrote in message
news:4Wswc.7616$4S5.2561@attbi_s52...
Yes, this is normal.

--
Tony
my boats at http://t.thomas.home.mchsi.com

"~Sam~" wrote in message
...
I have a 100hp Mercury outboard and have noticed that the tacho is
showing
some reading when the motor is stopped. If I turn the key to the "on"
position the needle will return to zero, but when I turn the key off the
needle will creep back up to usually between about 800 rpm and 2000 rpm.
When the motor is running the tacho works fine. I was wondering if this
is
normal for outboard motors???? Thanks..... Sam.