I know that to install a permanent Tach, I have to find a 20 pole version. But is there anyway to just check what my RPM's are with something else? I would like to verify my idle speed and RPM's at WOT. Can a regular automotive style hand-held tach work.... the type you clip onto a plug wire. Even if I have to divide/multiply the reading, would it still give me fairly accurate results?
I just picked up an optical laser tach from Amazon.com for less than $25. You put a piece of reflective tape on the flywheel, point the device. It reads instantaneous RPM, and has a memory function.
Its a great diagnostic tool for verifying that my instrument tach is reading correctly since its actually counting RPM rather than counting pulses on a signal wire. Downside is that it would probably be pretty difficult to use if the motor is not stationary, since you have to hold the laser on target for several seconds to get an accurate reading.