Looking for your opinion of these plugs

[EricJ]

5 minutes ago, teejayevans said:

It’s suppose to prevent stuck valves.
I use MMO before each oil change, Busch will tell you there is no evidence that works either. But he will tell you camguard works, because he use it in one of his engines...I would not call that evidence either.
Actually there are YouTube videos where they use MMO and then compare before and after, it does clean the engine.

My AP/IA recommended MMO for valve issues, and another AP that worked on my airplane indicated that putting it in the fuel rather than the oil was a bit better for valve problems.   If you put it in the oil it definitely takes the carbon out of the internals, which can be good.    As a practical treatment it seems to come recommended from a lot of pragmatic APs.   I had some in for the last oil change and a LOT of black stuff came out.

When I bought my airplane it was having a frequent problem fouling the bottom plug on the #2 cyl.   I found it'd be fine checking it at the end of a flight, but then the run-up for the next flight would reveal the plug to be fouled.   Don Maxwell told me to keep ground idle above 1000rpm, which I did, and which is also in the Lycoming Service Letter cited above.   Putting the fine wire plugs in the bottom cured it, though.

[ArtVandelay]

I would not put MMO in the fuel tanks, don’t know what effect it would have on the sealant.

[Andy95W]

7 hours ago, PTK said:

FWIW, Lycoming recommends it in a Service Letter. 

https://www.lycoming.com/sites/default/files/Spark Plug Fouling.pdf

I have great respect for Mike Busch and have learned a lot from his webinars. I also regard highly Lycoming’s recommendations and guidelines. I have learned and continue to learn from their literature.

Actually, the Service Letter says to run it at 1800 rpm for 15-20 seconds, then go to 1000-1200 rpm and pull the mixture.  From your original post, it sounds like you run up to 1700 for about 20 or 30 seconds "and then immediately pull the mixture."

Regardless, thanks for posting the SL.  I'm going to start doing that as it's written.

[PTK]

7 hours ago, Andy95W said:

Actually, the Service Letter says to run it at 1800 rpm for 15-20 seconds, then go to 1000-1200 rpm and pull the mixture.  From your original post, it sounds like you run up to 1700 for about 20 or 30 seconds "and then immediately pull the mixture."

Regardless, thanks for posting the SL.  I'm going to start doing that as it's written.

That's correct. My omission as I was typing. I do bring it back to around 1100 or so and leave it there ready for next start.