How to read RPM with a mulitmeter???

[BigBassin78]

I have a multimeter that will read RPMs for a 4, 5, 6, 8, cyl engine, presumably 4 strokes, and I want to read the RMPs. Is this possible and if so, what point to I need to touch my leads to in order to properly read RPM. I am trying to tune a new Tachometer.

 

[BigBassin78]

Re: How to read RPM with a mulitmeter???

Let me clarify my engine, sorry. 78 Evinrude 115, at what point on the engine do I need to touch the leads to to read RPMs.

 

[nwcove]

Re: How to read RPM with a mulitmeter???

not 100% sure, but shouldnt you be able to connect to the same leads that feed the tach?

 

[wilde1j]

Re: How to read RPM with a mulitmeter???

I think you have a 4 stroke dwell/tachometer, and if so, sorry it won't work with an outboard. You need a tach that will work off stator / reg/rectifier pulses.

 

[jimbo_jwc]

Re: How to read RPM with a mulitmeter???

Number of lobes on mag pu per revolution /meter on Hz and divide , must be able to get on mag leads

 

[laotou]

Re: How to read RPM with a mulitmeter???

Let me clarify my engine, sorry. 78 Evinrude 115, at what point on the engine do I need to touch the leads to to read RPMs.

In the Command Center, there is a gray wire in the electric cable. It is for tach. http://www.marineengine.com/parts/j...C&manufacturer=Johnson&section=Remote+Control

 

[Chris1956]

Re: How to read RPM with a mulitmeter???

Bigbassin, Your multimeter was designed to display RPM for a battery/coil/points distributor ignition system for a 4 cycle automobile engine. If your OB has a battery/coil/points ignition with a distributor, it may read accurately. That motor will be a 4 cylinder 2 cycle motor, so read it on the V8 scale, if it works at all

 

[F_R]

Re: How to read RPM with a mulitmeter???

He has Mag CD. Needs an alternator tach.

Bassin, if your tach is an inductive type, it will work, but I highly doubt that is the case because of the # of cylinders choice.