Lead in spark plugs!

Dayton Murdock · #1 05-12-2009, 10:13 AM

Hi All
Last night I removed the lower plugs to find lead nodules in my plugs!
What is the cause of this and how do I change this condition?
Running P-Mags with NGK plugs
EGT?s around 1280F
CHT?s 300F ish

mahlon_r · #2 05-12-2009, 10:39 AM

You could try running the engine up to 1200 or 1500 rpm for a minute or so, right before shutdown. That should get the core temperature of the plug above the temp that the lead will harden and thus hopefully keep the plug cleaner and make the lead clunkers a thing of the past.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

tc1234c · #3 05-12-2009, 11:30 AM

I do lean my engine and keep it lean until shut down. Yet I always find lead in my lower plugs. This is the tool I use to clean up plugs during oil change time:

http://www.aircraftspruce.com/catalo...theleadout.php

frankh · #4 05-12-2009, 11:39 AM

Mogas is the way to go my friend..I know your carbed but have you tried cruising LOP?...As long as you have the correct instrumentation you might be able to do it..You'll save fuel and its kinder on your engine too.

Of course most carbs won't allow running LOP but some apparently will.

Frank

Mike S · #5 05-12-2009, 01:34 PM

Quote:

Originally Posted by tc1234c

I do lean my engine and keep it lean until shot down.

I sure do hope you meant "shut down"

DeltaRomeo · #6 05-12-2009, 02:06 PM

It's common, Dayton. No worries, Mon.

Find a buddy who is a dentist and get him to give you a couple of those pointy things they scrap your teeth with. During oil changes remove the lower plugs and clean.

I've been doing this as part of oil changes for 7 years now. Leaning while taxiing helps reduce it, but you will get them.

b,
dr

frankh · #7 05-12-2009, 04:02 PM

Dayton your as cheap as me!...Gee for $5 for the bottom set of plugs just chuck 'em...

Frank

David Clifford · #8 05-12-2009, 04:44 PM

I have lead build up on the bottom plugs on my 0-235 L2C. I tried the high rpm shutdown method per Lyc, and just recently started adding the TCP fuel additive that is supposed to help. Well, after running through three tanks of fuel with the additive, I started to get hard starting and rough running. I pulled the plugs today and found the bottoms again built up with lead. Cleaned and rotated and she is running fine again. Doesn't look like the additive is doing anything.

tc1234c · #9 05-12-2009, 05:14 PM

Quote:

Originally Posted by Mike S

I sure do hope you meant "shut down"

Sure hope so

Dmadd · #10 05-12-2009, 08:39 PM

Auto gas with Marvel mystery oil mixed in will cure that. Put about half av gas half mo gas, but mix the marvel in the whole lot. (2 oz per five gallons.)
Engine will idle smoother too.

DM

Quote:

Originally Posted by David Clifford

I have lead build up on the bottom plugs on my 0-235 L2C. I tried the high rpm shutdown method per Lyc, and just recently started adding the TCP fuel additive that is supposed to help. Well, after running through three tanks of fuel with the additive, I started to get hard starting and rough running. I pulled the plugs today and found the bottoms again built up with lead. Cleaned and rotated and she is running fine again. Doesn't look like the additive is doing anything.