Over the years, I have accumulated a staggering array of different spark plugs for the Brison 3.2s. I do not keep track of the ones I use especially since I detect no difference in performance. I am more interested in reliability than getting the highest RPM possible. Except for the off brand plugs, do spark plugs perform differently?

Usually that's addressed through the quality and heat renage of the plug. A poorly made plug may not transfer energy well, or periodically misfire. Too hot or cold of a heat range can generate issues. The plug also needs to effectively handle the energy provided through our RC ignitions. Since you mentioned the Brison 3.2 you might like to know that particular engine, being Sachs based, is extremely tolerant of plug differences for numerous reasons. One is clyinder cooling area and another is compression ratio. The RCJ7Y is as good as any other plug on the market for that engine.

If a plug fits the reach and doesn't stray too far from the median heat range they will do fine. The better name brands typically provide the most consistent performance.

+1 what he said

Thanks TOM and Tim. That's what my experience shows. Dan

Just keep an eye on heat ranges. Different manufacturers have some rather wide standards of what defines a heat range. Mostly they all have a spot where most of them are pretty close to the same but when each manufacturer diverges from that point all bets are off. A single step up with one plug can equal 3 to 5 steps up with another plug. This is another area where the better manufacturers sahre more consistency. With many of the budget plugs you won't know what that difference is until you try it, and a little too much is a cooked off engine. If a low grade/low octane gas/fuel is being used the results can be disastrous.

FYI, heat range steps with iridium plugs are often big steps. The plug length can also change, impacting cap fit.

Many years ago I worked at a motorcycle shop and learned a few things about spark plugs. NGK plugs were 100% good right out of the box and never had reliability issues down the road. Champion plugs didn't work as well out of the box and were responsible for quite a few comebacks. I don't know if Champion has improved their plugs since then. Given the choice, I prefer to buy NGK for all my own vehicles and model engines.

Things have not changed much between then and now. Only the Champion advertising has improved.

A thought for those seeking to learn more about the spark plug subject. Visit the various manufacturer sites and learn what heat range your plugs fall under. Then learn more about plug interchangability between brands. Learn about "reach", "torque", "hex dimensions", "terminal types", "gaps", and other data that impacts spark plug selection and performance. There's a lot to learn.

Back in my drag racing days, I was a fan/user of Champion plugs, and they seemed to outlast most others in high compression engines. However, I noticed that the NGK plugs really did seem to work better/last longer in my motocross motorcycles. It seems like the quality of Champion plugs has declined over the years. Now I stick with NGK in most cases. Hey, we know they work, why mess around with other brands?

AV8TOR

You just used a revision of my favorite line. "If it ain't broke, don't fix it."

I went out and purchased a NGK cm6 for my rcgf 26 and Now I can't get it to run at all. Went back with the one that came with the engine and bingo it started.

I gaped (sp) the plug again and this time it started. It was set at about .018 and I reset in to .024. Still has a little high speed miss. but I can live with it.

Just about every CM-6 plug I've ever seen comes out of the box gapped at .018". Unless it was dropped on the end at sometime. That's what NGK tests them at. If you started out with a closed gap CM-6, you might think about using another plug. Good idea to check them when you purchase them if you're at some place where an exchange could be made. If a plug was dropped the ceramic could be fractured. Sometimes you can see it, sometimes you can't.

As things stand you maight want to go through all the connections on your ignition system. An NGK CM-6 runs almost forever when gapped at .018", so you have other issues in play.