Last Updated: September 10, References. To create this article, volunteer authors worked to edit and improve it over time. This article has been viewed , times. Learn more A tachometer is used to indicate the revolutions per minute RPM being performed by a car engine. Most cars with automatic transmissions are not equipped with a tachometer, since a tachometer is mostly used to indicate visually when it's time to shift gears.
A tach-dwell meter is a combination electronic device that measures engine rpm as a tachometer and ignition point dwell angle. The tachometer function is self-explanatory; it measures engine speed in revolutions per minute. The dwell function measures the degrees of distributor rotation that ignition points are closed and is directly related to ignition point gap. In fact, the ignition point gap can be set by adjusting the dwell angle. Attach the red lead on your meter to the negative "-" terminal on the ignition coil. Attach the black lead on your meter to any good ground on the engine; that is, an unpainted metal part. Set the meter for the number of cylinders your engine has.
Every engine spins within the limits of its design. The pistons inside the engine pump the crankshaft to spin. This spinning crankshaft sends horsepower to the street. A tachometer counts the number of rotations the crankshaft is making a minute RPM.
A tachometer is a device that measures the rotation speed of the engine of your motorcycle, and displays this information to you in an easy-to-read fashion. This provides the rider with a greater understanding of the work the engine is doing, as well as information on when to shift and a means by which to ensure good fuel economy. Unfortunately, many motorcycles, especially those of the cruiser variety, do not come standard with a tachometer. Get to know the performance of your bike better by installing a digital tachometer to your dash. Remove the tachometer from the packaging.