RPM Gauge/Tester

[Guest]

My automotive rpm tester doesn't work on a 2 cylinder engine. What recommendations do you guys have for a gauge/tester?

[HubbardRA 19]

Vibratach. This is a small hand held unit that uses a vibrating wire as the sensor. You hold it against the top of the engine, turn a dial that feeds a wire out of the unit, adjust the wire length till you get maximum vibration, then read the dial on the unit. These will work with both one and two cylinder engines. These have been used for years to check the governor settings on the stock tractors at the local tractor pulls. I think that both B/S and Tecumseh sell these units with their small engine tools. The one I have was sold by Tecumseh. I think they are made in Germany.

[D-17_Dave 12]

Your tester is set up for a 6 cyl. engine, right? Use it and multiply your reading by 3. This will give you an accurate count. If you want a no load speed of 3600 rpm on the engine, set your meter on the 6 cyl. engine and get a reading of 1200 rpm.

[Guest]

quote:

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Originally posted by D-17_Dave
Your tester is set up for a 6 cyl. engine, right? Use it and multiply your reading by 3. This will give you an accurate count. If you want a no load speed of 3600 rpm on the engine, set your meter on the 6 cyl. engine and get a reading of 1200 rpm.

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Nope, called the manufacturer and they said the unit won't work with 2 cylinder engines. Your thought was mine initially.

[D-17_Dave 12]

Does the meter you have operate off the ign. coil? I connect mine to the points side of the coil and it counts the times the points fire and mine works.

[Guest]

quote:

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Originally posted by D-17_Dave
Does the meter you have operate off the ign. coil? I connect mine to the points side of the coil and it counts the times the points fire and mine works.

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Yes but it just doesn't work. All I get are random meaningless numbers on it. As mentioned before, I contacted the manufacturer, Actron, and they said it would not work. Therefore, I didn't fool with it anymore.

[orangeone 0]

I bought a Tiny- Tach off of e-bay. One wire to the spark plug and the other wire to a good ground. Works on one and two cyl every time. I gave about $40.. bucks with shipping.

[Guest]

quote:

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Originally posted by orangeone
I bought a Tiny- Tach off of e-bay. One wire to the spark plug and the other wire to a good ground. Works on one and two cyl every time. I gave about $40.. bucks with shipping.

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That'll do the trick. Apparently they different models depending on whether the engine fires once or twice/rev, etc. Which one did you get and what engine are you using it on? I have the Onan 19.5 hp.

[RayS 79]

I use a tiny tach as well. Works great.

[orangeone 0]

There is several listed right now on E-bay . Make sure that it has the RPM and Hour meter . I use them on both 2 cyl and 1 cyl. One wire has a bolt down clip on it. I put a spring type clip on it and the other wire I wrap 4 times around the plug wire. This way I can use it on any engine.

[Mack 1]

Picked this up a few years ago at a garage sale.

With the AC on it I've seen them mistakenly listed under Allis Chalmers on ebay before.

[Guest]

Nice mechanical tach. Wish I had one but they're very expensive to purchase new today. Try about $150.

[Ronald Hribar 90]

I have some new mechanical tachs. However they are meant to be cable driven. Don't suppose an adaptor could be made so you could check shaft speed?

[BenB 3]

Beeser I use a tiny-tach on my Onans, it works well. I could not find a model number on the face, there is a paper label on the back with the number 3002NR, perhaps that is a model number. Mine works on my single cylinder engines as well. I believe the onans fire both plugs at the same time? Here is their site: [url]http://www.tinytach.com/tinytach/index.php[/url]

[Guest]

Thanks Ben. I couldn't see a 3002NR on the Tiny-Tach site but based on your description it appears that the TT226NR-2C or TT226R-2C should work. The cylinders only fire once/rev. Correct?

[MikeES 454]

I have used Tiny-Tach on several tractors. They work on all single cylinder Briggs, single and twin Kohlers (including electronic ignition) but they do not work on my 18hp OHV Kohler K361 single... I only get random numbers displayed on it???

[BenB 3]

Beeser, I found the orginal instructions for my Tiny-Tach. It gives no model number, but does say "Unless there is a specfic label on the unit, it is the standard model", which would be the 2C type.That should work fine on your Onan.

[Guest]

Thanks for the update Ben. I'll order one today.

[HubbardRA 19]

I mentioned the Vibratach above. Check this site for a picture of one. http://home.earthlink.net/~motorstuff/tools06.html You can purchase one at the site below. Go to Webstore, then Tecumseh, then miscellaneous. Price is only $14.50, hard to beat, and they work great. They sense the crankshaft rotational vibration, not the cylinders firing, so they work on all engines regardless of number of cylinders. http://www.perr.com

[Guest]

OK,I ordered one of the Vibratach units too but more out of curiousity.

[HubbardRA 19]

I also was skeptical about the little vibratach units. I had an electronic tach on one of my first stock pulling tractors. After having the tech officials check the max rpms week after week with a vibratach and seeing it always agree with the electronic tach. I became sold on these little units. This is the only type that I use for setting up my engines nowadays. Seeing is believing. Just take care of the unit and make sure the wire doesn't get bent. It will not be accurate if you get a sharp bend in the wire.

[dlcentral 1]

There a litlle digitach you can buy a places like northern.if you have a spark plug,,it will work,thats it clamp wire on plug wire and read it!,

[MPH 12]

Where might one find a tack like the one Mack shows? Only thing i've found is with snappon for over 300 bucks. Haven't justified that yet.

[Guest]

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Originally posted by MPH
Where might one find a tack like the one Mack shows? Only thing i've found is with snappon for over 300 bucks. Haven't justified that yet.

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Same place as Mack bought his, eBay. Type in 'hand tachometer' for a description and you'll find plenty of them. I don't know how useful they would be on a lot of our tractors, mine at least, because you generally don't have enough room on an end shaft to place the gauge.

[HubbardRA 19]

Marty, I borrowed one of those mechanical rotary tachs, like Mack shows, from a friend at work. Found out that I couldn't get it on the crankshaft of any of the tractors that I had. This is another reason I like the vibratach. You just hold it on top of the engine, or even the hood, and you can take the rpm reading. I'm not kidding, they do work that well.