Leo, about a year after I bought my Archer I started having chronic failed
mag checks with my O-360. I went through the usual high power leaning
procedure to get it temporarily cleared or, failing that, pulled the plugs
and dug out the crud with a straight dental pick (mine came from Sears.)

Then I discovered (U)REM37BY plugs and ground leaning. The 37BY plugs were
designed to run hotter and stay cleaner than the 40E's. For taxi I
aggressively lean the engine to near idle cut-off and keep the RPM around
1000 most of the time. When flying and not needing maximum performance, I
reduce power to 65% or less and lean to engine stumble, then slightly enrich
to obtain smooth power.

Since changing to the hotter plugs learning to lean as aggressively as
possible for the engine power setting, I have not had a bad mag check.

Best Regards,
Mike.

http://flickr.com/photos/mikenoel/
"texas slacker" wrote in message
...

Went out this morning and rolled the Warrior out for a little soul
restoring and piston oiling. It totally fulunked the run-up, tried to
burn the crud off the offending plug, no joy. Took it back to the
hanger and started pulling plugs. They all felt hot so I pulled them
in order. The crudded up plug was the last one. Didn't have anything
small enough to get in the massive type gap. Finally took the plug to
the mechanic and he dug out a special tool to gouge out the offending
material. Put the plug back in and Warrior passed the run-up. Flew
for a half hour just to be sure and made a good cross wind landing.
Life is good.
Now - I need to buy or fabricate some sort of gadget to do a decent
job of cleaning the plugs. In looking around I see that Chief
Aircraft has a sand blaster type for about $23. This looks possibly,
has anyone ever used this particular gadget and did it do the job?
Anyone have a better suggestion? Thanks. Leo