Spark Plug Tachometer - good enough?

[cmayo]

I just completed a repair on my Troy-Bilt XP/Kohler Courage 20 SV600 lawn tractor that required me to remove the speed control bracket. Now that it's all back together, the engine is running at a too-low RPM. it looks like adjusting the RPM is pretty simple but I'd like to use a tach to make sure I'm staying reasonably close to spec (Kohler service manual: Recommended maximum no-load high speed (RPM) for most engines is 3300 RPM).

I don't want to spend money for a tool (tach) I'll probably never use again, and I can buy a spark plug Tach on Amazon for cheap but don't know if it's going to be accurate enough to be of any value. Anyone have any experience with these type of things (attached)?

Amazon.com

 

[Skippydiesel]

They are far from precision tools. If cheap enough, purchase two & compare the reading.

 

[MParr]

Cheap ain't good and good ain't cheap.
If you are going to buy one, get one that's a little more expensive. Look for one that only gives the RPMs.
I bought this one.

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

www.amazon.com

 

[cmayo]

They are far from precision tools. If cheap enough, purchase two & compare the reading.

I like your thinking here and I may do just that. I can always return one (or both)

 

[cmayo]

Cheap ain't good and good ain't cheap.
If you are going to buy one, get one that's a little more expensive. Look for one that only gives the RPMs.
I bought this one.

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

www.amazon.com

Thanks for the recommendation. I actually ordered the one I posted but am thinking of getting a second one to compare readings, as @Skippydiesel suggested, and will probably go with your recommendation. Thanks again!

 

[slomo]

Cheap ain't good and good ain't cheap.
If you are going to buy one, get one that's a little more expensive. Look for one that only gives the RPMs.
I bought this one.

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

Amazon.com: Runleader RL-HM019J Digital Tachometer with Alligator Clip, Max RPM Display, Waterproof Design. : Patio, Lawn & Garden

www.amazon.com

You can't buy expensive tools on this site. Been scolded several times now about spark testing tools LOL.

 

[MParr]

You can't buy expensive tools on this site. Been scolded several times now about spark testing tools LOL.

Old school spark testing tools are free.

 

[MParr]

Thanks for the recommendation. I actually ordered the one I posted but am thinking of getting a second one to compare readings, as @Skippydiesel suggested, and will probably go with your recommendation. Thanks again!

I didn't need the hour meter or service reminder functions. They are only good if you are permanently mounting it to the machine.

 

[Skippydiesel]

I check rpm, on a verity of engines, single to four cylinder, about once per annum.
To reduce error, I usually use a couple of photo types and a wire in/spark plug lead digital tacho. If the machine also has its own tacho, I end up with up to four comparisons (usually just two) - go with the average, reading works for me.
NOTE: A reading that is way out of whack with the others is investigated/adjusted ultimately, if not brought into line, ignored.