HELP! Oppama PET-4000 vs Stihl ZAT-4 which ignition tester is superior?

[Sawponder]

Which ignition tester is superior? Looking for one that can replicate/test spark under compression....to weed out those weak igntions that spark with the plug removed and dont fire once installed

Thanks in advance

 

[hacskaroly]

I have used a ZAT-4 in the past at work and it works fine, now I just hold the end, pull the rope and wait for the tingle...

 

[Sawponder]

I have used a ZAT-4 in the past at work and it works fine, now I just hold the end, pull the rope and wait for the tingle...

I need one thatll point out a weak ignition, the ones thatll pass a visual spark test but completely/partially fails while under compression

 

[EFSM]

No experience on the Stihl. I've used the Oppama for years. They come with the weird alligator clip on the end--replace it with a spark plug terminal. They work well; there's no replacement for an adjustable spark stress tester.

 

[av8or3]

You may find this interesting. The spark plug tester we use uses shop air to simulate compression. Spark plugs fire best under compression and sometimes won’t fire at all without it.
Not sure why.

 

[Sawponder]

You may find this interesting. The spark plug tester we use uses shop air to simulate compression. Spark plugs fire best under compression and sometimes won’t fire at all without it.
Not sure why.

Is it creating a vaccum or pressure on the plug for testing?