Specs for external "shop" tachometer

[ShoalSurvivor]

I'm looking to pickup a shop tach to adjust idle and set timing on my 2004 Mercruiser 4.3
Will one of these $20 "small engine" tachs to the trick?
Amazon Tach
are they all "pulse" tachs?

I'm looking for a wired version to connect to tach pigtail on the harness (purple / grey), but the all show clamping into or wrapping the spark plug wire.

Recommendations and instructions for hookup would be greatly appreciated!
thanks,
Michael

 

[Scott06]

I'm looking to pickup a shop tach to adjust idle and set timing on my 2004 Mercruiser 4.3
Will one of these $20 "small engine" tachs to the trick?
Amazon Tach
are they all "pulse" tachs?

I'm looking for a wired version to connect to tach pigtail on the harness (purple / grey), but the all show clamping into or wrapping the spark plug wire.

Recommendations and instructions for hookup would be greatly appreciated!
thanks,
Michael

normally a shop tach is for temp hook up either on a plug or the negative side of the coil. if you need a timing light I would get a timing light with a tach. I keep waiting for my old dial back timing light to die (1990 vintage...)

https://www.amazon.com/INNOVA-3568-Digital-Timing-Light/dp/B000EVYGV4/ref=sr_1_1_sspa?crid=CTY29KVHZ6LX&dib=eyJ2IjoiMSJ9.4ZbCTDeQJCogcmmh_p9Xx7jLs6LrWLFxxJljs9Z0QfAzGrLvyXxHiFwoXt9U92rsgorPu3coecyI8kg1JAFynGX7tErMPXe4T-DpXPA-ZZyURvfqGQb57NDp7J6RtsCP0xGRDdYKLYNDbyG0XxjrG0SBFDOdq58Ydc-RDqE-gAtWNwh-djJm8wcxgCzgm6Zc7sfdBmn5YP_tXdtNR-23mbALQUQCC9WzGa3j8jyCIxo990s1hgalUoarxucn-JM7HW-J9qzTrowk2YnxSLBjnvelUy1sll2pXO94cPCrwo0.3kJCbqGVU_zXvBCD-9ZUkw0gO8JIZ8h1LB5fOmkV7vQ&dib_tag=se&keywords=timing+light+with+tach&qid=1773692786&sprefix=timing+light+with+tach%2Caps%2C135&sr=8-1-spons&ufe=app_do%3Aamzn1.fos.9fe8cbfa-bf43-43d1-a707-3f4e65a4b666&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

I bought this because it also does the KV of the spark which can be helpful when trouble shooting , but its a little pricey. Nice that you just hold it close to the engine and can do any cyl or stroke combo ..

https://www.amazon.com/General-Technologies-Corp-TA100-Tachometer/dp/B000RT9BH2/ref=sr_1_2?crid=1KGD5TBIPVR3G&dib=eyJ2IjoiMSJ9.a2TFglInpkeUAyqGr_294einntqUq932DL1_m0MNrcCSDIBVLD7TCqptPelhFxMmcUDofAesfx65N8miCZ0Vq9Of_ZRuEaQXx-bIEg3LV14ctOYezH-5M0Q9_SR5h7CryqrOYm0CAZPXytbIlw3yvAwTlcmjJ-9AT1Ljqxy-O75xVc6P6CxPdVGHsSg6r2iq4KTptuNxV-t_O2bP_BW1P0jVHzsgJShbqexIOUwXDKmBxeOefYeh_mfePfWHcUxl9bbkg1z0AGdFlwNwgj7JhyU9h4Pt4fTkec5lOf8sark.EutKTvFmrFoIAIh4abqlhFZZEzuGcCFeWrWu4_dwjZE&dib_tag=se&keywords=ignition+analyzer&qid=1773692619&sprefix=igntion+analyzer%2Caps%2C147&sr=8-2

this has a tach feature also is a VM-

Amazon.com: ALLOSUN EM127 Digital Automotive Meter Digital Multimeter RPM Dwell Angel Ignition System Test Duty Cycle Measurement 1999 Reading LCD DCV DC Resistance Measure : Automotive

Buy ALLOSUN EM127 Digital Automotive Meter Digital Multimeter RPM Dwell Angel Ignition System Test Duty Cycle Measurement 1999 Reading LCD DCV DC Resistance Measure: Multimeters & Analyzers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[dingbat]

I have one similar to the one posted. Use

I'm looking to pickup a shop tach to adjust idle and set timing on my 2004 Mercruiser 4.3
Will one of these $20 "small engine" tachs to the trick?
Amazon Tach
are they all "pulse" tachs?

I'm looking for a wired version to connect to tach pigtail on the harness (purple / grey), but the all show clamping into or wrapping the spark plug

i use one similar to the one you posted to adjust idle on my small, two and four stroke engines.

Came as a “wrap around” but added a battery clip to make it a “clamp-on”. Works well for the purpose. No complains for the price

 

[Scott Danforth]

I have a laser photo tach I use on 2-strokes

I have 5 old tach / dwell meters that I use. One of them was my father's from the 60's, one is mine from the 80s, and the other is from my wife's late father and 2 from a garage sale. Paid $8 for the last two about 2 months ago

My recommendation is hit your local garage sale

 

[Scott06]

I have a laser photo tach I use on 2-strokes

I have 5 old tach / dwell meters that I use. One of them was my father's from the 60's, one is mine from the 80s, and the other is from my wife's late father and 2 from a garage sale. Paid $8 for the last two about 2 months ago

My recommendation is hit your local garage sale

Same here the sun tach and dwell I bought in 1990 ish died, so I use my fathers that he bought in the 60 s, still works. garage Sales and FB market place are good places to look.

 

[Bondo]

I'm looking to pickup a shop tach to adjust idle and set timing on my 2004 Mercruiser 4.3
Will one of these $20 "small engine" tachs to the trick?
Amazon Tach
are they all "pulse" tachs?

I'm looking for a wired version to connect to tach pigtail on the harness (purple / grey), but the all show clamping into or wrapping the spark plug wire.

Recommendations and instructions for hookup would be greatly appreciated!
thanks,
Michael

Ayuh,...... I used to have a tach/ dwell meter set up, 'n a timing light, but when the tach/ dwell meter grew legs, 'n my timing light died, I bought an Innova timing light, that does it All,....
My Innova timing light,....

 

[Lpgc]

I'm looking to pickup a shop tach to adjust idle and set timing on my 2004 Mercruiser 4.3
Will one of these $20 "small engine" tachs to the trick?
Amazon Tach
are they all "pulse" tachs?

I'm looking for a wired version to connect to tach pigtail on the harness (purple / grey), but the all show clamping into or wrapping the spark plug wire.

Recommendations and instructions for hookup would be greatly appreciated!
thanks,
Michael

I fitted a 'Runleader' digital tach and multifucntion display 1 from Amazon on my boat dash because I don't trust the old analogue tach, it is similar to the tach you linked to and works with my I/O V8, can be set to give correct tach reading for 4 and 2 stroke engines with just about any number of cylinders and coils. Mine is wired to the single coil so is set for 4 pulses per revolution but it was advertised as suitable for any engine and able to work with coil or tach pulses.

It was working perfectly with a single discrete wire running from the coil to the unit. But then I ran 2 core wire to use one wire for the tach and the other wire to add a temp sensor to the engine to use with the Runleader's temp display, which seems to have caused it to read double rpm at low rpms. To correct it reading double at low rpms I intend to either try connecting a small capacitor between earth and the temp sensor wire or run a separate feed for the tach and temp gauge, I believe the double rpm reading is caused by the tach signal inducting a second pulse on the temp wire in the 2 core.

Obviously for checking ignition timing or spark quality you'd need to use something else, I use an old-skool strobe on my basic carb and distributor V8 for setting timing but it's nice to have the spot on correct digital rpm reading on the dash and a second temp gauge, I don't trust the old dash temp gauge either.