3 cylinder tach

Karl I can't find one right off hand but I had a tach that used an inductive pickup off the plug wire to drive the tach. I guess it would work on any number of cylinders as long as they only fire once per revolution. Steve

Tiny-tach or other secondary triggered tach connected to one plug wire. Doesn't care how many cyls - there are 2 types - 2 stroke and 4 stroke. 2 stroke tach works with double ended coils, which are NOT used on 3 cyl engines.

** Posted from **

"Karl Townsend" wrote in message news:48278ab7$0$87934$ snipped-for-privacy@auth.newsreader.octanews.com...

There are a bunch of units out there that use sources other than the ignition for tach input. Does the tractor have an alternator? Alternator tachs are common. Lots of engines use a hall effect transducer reading a magnet in the flywheel. I've even seen one setup that used a proximity sensor reading the fins on the generator fan.

What you are looking for seems to be more akin to the readout on a stationary power unit.

Give the folks as Isspro in Portland OR a call----(888) 447-7776. They are who I've used for mobile equipment instrumentation for years.

Bill

I'm in a similar boat with the 3cyl diesel tractor I just got (used). Looking at the various commercial offerings I've seen a few that read off the A/C from the alternator, and another that uses a hall effect sensor and a magnet you epoxy to something rotating. I'm not real happy with the prices on them however and am considering just building my own unit using a hall effect sensor.

Thanks, I just ordered a tiny tach. I don't like that it has a sealed battery and will only last 4-5 years and then need to be replaced, but that's the way everything is built now.

Karl

** Posted from **

I have read all these posts. This is NOT an application for an electronic Tach. Use a mechanical Tach. They come in 1-1 and 2-1 flavors and are very accurate at low speeds. Steve

When the time comes, freeze the unit in the freezer overnight and give it a rap along the sealing line in the morning and see if it cracks open easily.

Wes

Why is such accuracy needed in a tractor? If you are driving an alternator get the cps from the load.

Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/

I will use it to apply fungicide and insecticide. I can get away with using

1/2 what the label calls for but not 3/8. These companies call out higher rates just because most don't apply accurately. In my case, I save about $3K per year. Plus, its good for the environment, yada yada.

Karl

I hear ya, but don't see any offerings. Do you have an example product?

Karl

Google on "tinytach". they use a sensor on one injection line and don't care how many cylinders you've got.

Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

I've seen this done. A friend used a knock sensor for a GM car, attached it to a diesel injection line.

Sweet.

Gas or Diesel?

Gas is easy. Use a 6 cylinder electronic and look for 2400-2600 rpm - ie, a 6 should just read double what a 3 is actually doing. Adjust your brain (or the industrial strength post-it stuck to the dashboard) and it's easy.

Diesel is more difficult.

"Karl Townsend" wrote in message news:4828452e$0$218$ snipped-for-privacy@auth.newsreader.octanews.com...

For well under 3K you could install a spray controller. I'm most familiar with Raven, was a service tech for years. Also Dickey John and Spray Systems, and a few others are popular.

Install unit, set for desired gallons per acre, and drive.

Bill

I've seen an article somewhere on the web about changing the battery and resetting the hour meter, but I don;t remember where...

Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

OK, that brings up a question. How does an alternator tach work? Or I guess more importantly, how does it know the engine rpm based on the alternator speed? If I have different pulley ratios than the calibration for the tach won't it be off? I can easily follow that it is picking up on the frequency of the AC in the alternator, but never figured out how it "knew" the correlation to engine speed.

Inquiring minds would like to know...

JW

Are you trying to determine your traveling rate(mph), or the pump speed driven by the PTO, or?

JW