I've got a friend with one of these plugs. He used one of these to do basic tune-up when setting up his blown engine and said it works great for low-cost item.

He might have it still in the garage.

Have you used one of these? What's your experience?

Thanks!

Don't know what it is. Can you provide more info?

https://www.youtube.com/watch?v=Y9t8XhFlKbk

I checked the price in Australia and they want $110 for one !

regards,Rod.

I don't think guys like Jack Rousch, and Junior Johnson will be running out to buy these. In fact I think I just heard Smokey Yunick spinning in his grave. LOL! Pretty cool invention though. The inventor was certainly thinking outside the box.

these were the thing decades ago, but the biggest handicap is you can only use them at idle, more or less. can't rev high and can't load the engine. And judging optimal color is still subjective, everyone sees or understands the colors differently. Nice old school tool for setting idle mixture in the ballpark, but that's all its good for You would get equally accurate results by listening to rpm changes while turning mixture screw. Or reading real spark plug insulator color after a run. Buy an O2 sensor bung and weld it on the exhaust and use an O2 sensor and a voltmeter, to get a true reading.

Thanks for the tips! I had accidently left off the video, it's pretty cool. My friend hasn't found his old plug yet. If he does, i'll get a video for you. His experience was that it was good for correcting big problems. He was adding a blower to his motor and accidently made a mistake. Colortune plug helped him find the mistake.