How To: Use a Small Engine Tachometer & Set Engine Speed | Reviewing the Cheapest One On Amazon

In this video we take a look at how to use a small engine tachometer, adjust our engine speed for maximum RPMs, and see if the cheapest one off of Amazon is any good.

We are using my re-powered Ariens Compact 22 snow blower as an example to make sure we are running within the original engine's specifications.

How do you know if you need to check and adjust your engine speed?

-When you're doing a small engine swap and need to match the performance of the outgoing motor.

-When you are dealing with generators, you want to make sure your RPMs are in-line with the manufacturer's specifications. (RPMs have a direct relation with a generator's output voltage. Make sure you're not frying anything you plug in.)

-When your machine doesn't seem to be performing as well as it should. Your RPMs may have dipped below spec, and a quick adjustment can fix that.

[baldeagle]

Thanks for sharing this. I bought one of these some time ago and never could get it to read correctly. I'll have to get it out again and play around with it.

[nowayjose]

Need to bring it up to operating temperature first before setting the set screw.

[CuriousKL]

A heads up. The lock nut that holds the throttle lever can loosen because of vibration. Tighten that lock nut just a bit and apply some light lubricant. Don't use WD40. Then make your speed adjustment.

[johncollins]

I just saw this on some website (something 'wizz') but couldn't see comments so searched Ytube. Thanks for this. I've stayed away from anything with wires and/or that spoke of hour - counter but you've just taught me this type should do what I want -' just to test speed occasionally on different engines. I have a branch shredder with Honda GC 135 that just stalls when I push a correct diameter branch in. My Briggs vibrating doodad shows only 1900 rpm! It needs to be 3600 so I need to check the reading and figure out how to increase the speed (I don't think it's as simple as yours). •Steve 's Small Engine suggests to bend the lower tab on the governor that has the little spring attached. But for now I'll buy one of these things when I've checked out the reviews. THANK YOU!

[stephenschrader]

I've used five of these cheap amazon or ebay tachs and they all tested accurate against Faria Beede tachs. 3-4 loops tightly wrapped with zip tie works well.

[mrbrown]

DIAGNOSTIC PRO TIP:
Wrap 5 turns around a round metal bar 1/4" diameter, 1 inch long.
Wrap that with duct tape to keep wire on the bar,
and not unwinding like the Graz attempt.
Zip tie it to a spark plug wire and start your engine.
When done adjusting engine RPM, cut zip ties
and move to the other cylinder, if necessary.
You have just created an inductive bar.
It steals the pulse from the plug wire, and
applies it to your metal bar, where the device
accurately detects and registers it.
I cannot tell you the device is accurate,
but you just removed a lot of the variables.
-- The Great Nicolas Tesla revealed these secrets 100 years ago.
-- North Central Florida
-- 9.10.2023

[CookedAnimalEater]

Oh...now you're an expert with the 7th loop.

[wryanddry]

5:01 Secure the wire using a clove hitch on each end. Also maybe a couple dabs of hot glue.

[LogiForce]

Tip, buy a small batter clamp and solder the wire to the clamp. That way you can easily attach and remove the tacho on any engine.

[mickgatz]

Very informative video!
you gotta be careful when winding the wire.
Too many, and you'll get a 'false' higher RPM
Too few, and you'll get a 'false' lower RPM
(there's a bit of a trick to tweak them apparently)

I've basically got the same tach that I bought about 5 year ago.
It has a replaceable battery (CR2450).
However, I just found it in my box of junk and decided to hook it up.
Not sure if the hours will be erased once the battery is depleted. I expect it so for a cheap unit. :)
Fingers X'd
Cheers!
Mick

[thegunnut]

You wrapped the wire around the double insulated part of the spark plug lead. Inaccurate reading if wired like this.

[myparadiseonbantayanisland]

3600 rpm is usually the redline for single cylinder lawnmower type engines.

[biggusbestus]

Guess the Honda 216 engine is not typical they call for 3, 100 rpm no load rpm ... thanks for the video I have one on order.

[PaulHenreid]

The Operating Instructions for this self powered digital tachometer state: "4 stroke installation, wrap pickup wire around head of coil. 2 stroke installation, wrap pickup wire around spark plug lead."

[louvega]

Good vid, thanks Graz. I have a DR650 motorcycle which has no tacho and runs a carb, which needs adjustment according to conditions. I was looking for some way to meet and check the idle RPM. Any reason you can see why this would not work on the bike? It's a single cylinder engine with two spark plugs.

[reesemolloy]

Also how do I install one on a twin cylinder engine

[stclairstclair]

I think I'm going to verify this unit with a handheld tach-meter, I'm a retired mechanic and I want to see if I can successfully wind my sensor wire near the coil under the engine cover, I just built a sweet vintage style go kart.

[kevinspahr]

Can the wire be permanently wrapped around the spark plug wire and mounted and used as a tachometer for my motorcycle?

[reesemolloy]

So I’m guessing the spark plug makes power for it?

[stanleykeith]

I just ordered one of these and I was wondering if you can cut some of that extra wire off. I'm glad its on a snow blower. I also have an Ariens 24". Please let me know about the Extra wire. Thanks for sharing.