Magnetic Tachometers?

[Tmacular]

I have seen those newer style tachs that have the magnet u place on the flywheel and as it spins it counts the rpms to a remote read out, anyone ever use these, do they work on the older motors where tachs are hard to find?

 

[wickware]

Re: Magnetic Tachometers?

I had a miniature tach that worked off the # 1 plug wire for 10 years or so before it stopped. It had signs that moisture got to it over the years. I w/n concerned how accurate it was vs letting me know I had dropped RPMs that I had when it was running good. I am the Tach now on my 1970 35 HP Chrysler. LOL. I doubt that I searched for another nor did I find a name on the attached unit. Probably any Inductive Auto Tach would serve the purpose I used it for (but not at the prices at the link below). jow

http://www.bing.com/shopping/search...t=inductive+auto+tachometer&FORM=HURE#x0y4158

 

[Justinde]

Re: Magnetic Tachometers?

Same thing as the electronic speedo I used on my race motorbike. Put a sensor on the front disk brake, and a sender unit on the yoke, and the speedo worked off a magnetic pulse. Same theory I suppose, just counting pulses. Make sure the pick up isn't so big as to put your flywheel out of balance.

I now have a 'tiny tach' for mine. Seems to work a treat.

Cheers

 

[Tmacular]

Re: Magnetic Tachometers?

Same thing as the electronic speedo I used on my race motorbike. Put a sensor on the front disk brake, and a sender unit on the yoke, and the speedo worked off a magnetic pulse. Same theory I suppose, just counting pulses. Make sure the pick up isn't so big as to put your flywheel out of balance.

I now have a 'tiny tach' for mine. Seems to work a treat.

Cheers

Yes thats exactly what they do. I would think that its pretty accurate, but I have never used one on anything. I can pick one up around the 50$ range.

 

[Justinde]

Re: Magnetic Tachometers?

My Speedo was within a poofeenth of 100%- it's how you set it. I would imagine the instructions will give you something like ' set at TDC, measure flywheel, turn flywheel, measure and set firing order' Bingo Bango, a new tacho. Again, just make double sure that the flywheel isn't out of balance.

Cheers

 

[Tmacular]

Re: Magnetic Tachometers?

Is there a specific way to keep the flywheel from throwing its balance? If I go with this route, is there a suggested spot to install the magnet?

 

[Justinde]

Re: Magnetic Tachometers?

I'd go a Tiny Tach- bought mine on ebay for $35.00. Extended the coax cable for $15.00 and senses the spark. I wouldn't mess with the flywheel. Reccommended INstallation to minimise balance issues- anywhere but the flywheel!

 

[Tmacular]

Re: Magnetic Tachometers?

LOL, I guess that makes sense. I will look into those tiny tachs and at 35$, thats a little cheaper then what I was going for. Does that have a digital read out, or a standard tach?

 

[Justinde]

Re: Magnetic Tachometers?

Its a digital readout, and about 2.5 inches wide by maybe .5 inch high. It measures actual engine hours, and is suitable for outboard use- just get the right one....

http://www.tinytach.com/tinytach/gasoline.php

 

[Tmacular]

Re: Magnetic Tachometers?

Excellent, seems like a suitable candidate for my outboard. Thanks for the info and reference.