# Ways to clean Iridium Spark Plugs

### Help Support HomeBuiltAirplanes.com:

#### Daleandee

##### Well-Known Member
They say there are no stupid questions so I'm gonna test the waters on that ... :gig:

I know how to clean a spark plug but iridium plugs are pretty "tender" so care needs to be taken to clean them without breaking the tip. I've looked online to find several suggestions but thought that posing the question here would get me several valuable answers and perhaps someone has a great tip that is not well known. The cost of replacing the entire set of plugs is less than $35.00 so expensive cleaning methods need not apply. My plugs look great and don't have many hours on them. Still, while I have them out during the condition inspection, I'd like to clean them up. Just for clarity you should know that I'm using Denso Iridium auto plugs in a Corvair conversion in my aircraft. May I also inquire whether rotating the plugs might also be a good idea? Seems it would be but I'd also appreciate the groups thoughts on this. Thanks in advance, Dale N319WF #### TFF ##### Well-Known Member I use a strong 90 deg pick and dig stuff out. There are vibrating cleaning tools. You could probably make one with a flat tip soldered to the end of an electric etching pen. How do regular plugs do? Cheaper and pitch every 50/100 hours may be the ticket. That is what a friend does with his RV7 on electronic ignition. #### TFF ##### Well-Known Member I will say that another friend has lead issues with his O-235 and had to put in the special long reach plugs to keep them from fowling. they needed cleaning often with regular plugs; long electrode special plugs would still fire even if loaded up. #### Toobuilder ##### Well-Known Member HBA Supporter Log Member Its my understanding that iridium plugs are "self cleaning" by virtue of them running super hot at the tip. If they look cruddy, replace. #### Daleandee ##### Well-Known Member Thanks! I was using regular plugs and replacing them during the condition inspection even though they still looked great. Then I went with the iridium plugs and it seems to start easier and run smoother. The plugs can be had for ~$35.00 for the set so even replacement is still pretty cheap.

There is no build up on the current plugs they just have a light gray appearance between the insulator and the plug body ... nothing that would require being dug out. Some suggestions I found were to use high heat (Map Gas maybe?) to burn them clean or even some chemical and a nylon brush. But all of that appears to be much more than mine would need. I'll most likely wipe them down and rotate the install placement.

What Toolbuilder says about them being "self cleaning" appears to be true. So wisdom says to leave them alone.

Appreciate the feedback ...

Dale
N319WF

#### TFF

##### Well-Known Member
I know I can tell how good a pilot leans his aircraft by looking at plugs. I clean the aviation iridium plugs all the time, but they are delicate. I like to spray contact cleaner on plugs after I clean them. It does a good job washing them out. Sounds like a great running engine.