Testing Spark Plugs Using An Ohmmeter

[slomo]

Had a 24 plug shop pack of J19LM that all failed within 10 minutes of first run after installation

Which means someone dropped them probably in shipping.

slomo

 

[slomo]

You guys got it ALL wrong. I've never seen so many supertechs argue over a spark plug. This is like "what is the best oil to run" flame war. Break out the popcorn.

slomo

 

[slomo]

Inline spark testers showing false positives LOL

Bummer there. How did they fail? internal short?

If they were shorted they would ALL work.

slomo

 

[slomo]

I wonder if those were part of the ones that were the first batches out of Mexico. They had problems when they first opened the plant there.

And today is 28,000,000 plugs later. Probably safe to rule out Mexico.

slomo

 

[Hammermechanicman]

Inline spark testers showing false positives LOL

If they were shorted they would ALL work.

slomo

By internal short i meant the plug arcs internally from the center conductor to the metal shell.

 

[ILENGINE]

Which means someone dropped them probably in shipping.

slomo

That was also my thought, but that styrofoam packing box that Champion shop packs come in would of had some serious damage.

 

[slomo]

That was also my thought, but that styrofoam packing box that Champion shop packs come in would of had some serious damage.

Remember they have ceramic insulators. Either a bad batch or they were dropped. One thing for sure is they went like hot cakes.

slomo

 

[slomo]

By internal short i meant the plug arcs internally from the center conductor to the metal shell.

Electrically speaking, that is not a short. Shorts are caused by excessive current, blow breakers and burn wires and houses down. I know what you meant. Just busting your chops LOL.

slomo

 

[seattlepioneer]

How often did a new plug fail testing?

 

[seattlepioneer]

You can't look at a spark plug and tell if it is good or not. You need special equipment to test a spark plug. For $2 it is more expedient for a shop to replace a plug and see is that solves a spark issue rather than looking for a high tension spark plug tester. Some of us buffons running small engine shops may have some skills other than mowers. I serviced printing equipment for 40 years. Some of it multi million dollar systems with some single repair parts costing thousands of dollars. You better be able to troubleshoot logically or else look for another job

when aircraft were in for scheduled maint the plugs were removed, cleaned and tested. If they failed they wefe replaced. Some radial engines have 36 cylinders with two plugs per cylinder and 2 or 4 engines. With 2 engines that is 144 plugs and at close to $10 a plug aircraft owners don't want to drop an extra $1500 for plugs. Yes we tested and documented new plugs.

That seems like a good plan for reliable operation!

Presumably the second spark plug is for redundancy should one plug fail. Then have regular maintenance scheduled with each plug being tested to catch any that might have failed, and test new plugs to be sure they are good. How often did you find one of the two plugs failing the test, and how often was this maintenance was performed?

Thanks for the interesting story!