How to tell if all my cylinders are firing?

You can check the temp of the exhaust primaries.

 

Several symptoms will tell you that not all of the cylinders are firing, engine stumbles on acceleration and going around sharp corners could result in unburnt fuel getting into the manifolds/headers causing backfiring. As mentioned, a infrared temp gauge reading on each of the header primaries will indicate the offending cylinder(s).

 

you may use a strobe light

long ago champion had a small tester like a pencil

 

They are still made.

https://www.amazon.com/Lisle-19380-Spark-Tester/dp/B0002STS3U/ref=asc_df_B0002STS3U/?tag=hyprod-20&linkCode=df0&hvadid=312142020868&hvpos=&hvnetw=g&hvrand=16821307322114786987&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9004488&hvtargid=pla-494321916635&psc=1

But that only tells you there is spark at the wire, not at the plug, or if the cylinder is actually firing as an exhaust temp reading would.

 

you are right andy, but if the indicator not shows anything then you just know. when the champion indicator works then there is a spark. but may be the spark is between the spark plug plug and ground. but you know then that there is a spark.
thank you for the link, have not known that this great tool is still available, helps me more than once

 

You can remove the spark plug lead one by one and see if it makes a difference when pushing it against the spark plug top....wear protecting gloves !!

 

I bought 12 of these. They go between the lead and spark plug. Good way to see if everything is firing. https://www.ebay.com/itm/171689611692?epid=1224726846&hash=item27f97f91ac:ggYAAOSwtSFh8WT4

 

how you can see if they work? the spark plugs are deep in the cylinder head

 

They stick out just fine. They sit on top of the spark plug electrode on top, then you plug the lead in to that. They're about 3-4 inches tall, so they stick out just fine. You can see the lights flickering when engine is running very easily.

 

can you post a photo please?

 

I think that he meant that it goes between the spark plug wire end and the extender (so it hangs out a fair bit from the camcover enough to see and the molded rectangular plug on the end of the spark plug wire is not in the camcover -- so, even if you cant see the whole thing, the "flash" in the cavity of the camcover can be seen). It's got the wrong kind of connections to go between the extender and the spark plug.

 

that would make sense, but even then you not know 100% if there is a spark at the spark plug or before somewhere, so between a bad extender and ground from the head

 

Yes, agree. It only confirms that the ignition system is correctly sending a spark pulse down the spark plug wire -- it doesn't confirm if the spark is jumping the spark plug electrodes or if it finding some other path to ground.