Time between sparks plugs

[Ernie Martin]

I change them "on condition", that is, not at a set time but when their performance and appearance suggests a change. Typically, I inspect all plugs when the annual is done, since they come out for the compression check.

I would guess that they have been lasting about 500 hrs, but this is just a guess. It also depends on how you run your engine and probably whether it's a turbo or not. My experience is with normally aspirated and running at cruise 50-75 degrees rich of peak EGT, a setting which in my experience keeps the plugs nice and clean.


Saludos,
Ernie