Tachs should be marked according to the limits set by the manufacturer of the engine installed.
John described the markings for a C-85. 600 RPM is the idle speed recommended by Continental. Other markings should be different as applicable to a A-65, C-75, C-90 or 0-200 installation (or if a used tach from another aircraft with a different engine were installed "as received"). At one time there was a range of RPM in which sustained operation with the McCauley props was not recommended. While McCauley officially rescinded the limitation, a tach from the earlier era would properly have had that range marked. I don't know what color would have been "acceptable to the Administrator". Regards, WRB -- On Mar 9, 2010, at 11:35, Donald wrote: > > > That is strange, I never thought about it, but mine came to me wth > arcs marked as follows: > 600-1900 Amber-yellow > 1900 to 2625 Green > 2625 to 3050 Red > > I wonder if this has changed somewhere along the line? > --- In [email protected], John Cooper <j...@...> wrote: >> >> On 3/9/2010 11:14 AM, my_ercoupe wrote: >>> Can anyone tell me the proper ranges (markings, green,red, etc) to >>> put on the tach? >>> >>> >> Green arc 500-2575 Red radial at 2575 >> >> Shameless plug: Skyport tachs come premarked. >> >> -- >> John >> Skyport East >> www.skyportservices.net >> > > > > > ------------------------------------ > > Yahoo! Groups Links > > >
