For the engine, the higher the RPM the better. However, 1800 is used
because its a high RPM but doesn't suck as many rocks into the prop as
full RPM. If you run up to full RPM everytime you'll send up replacing
your prop every annual.

-Robert



"Roger Long" wrote in message ...
I can't remember where I "learned" it but I always thought 1800 RPM was the
limit for ground running leaned to clear plugs. I had a really bad one
yesterday with 250 RPM drop. I taxied back to the shop and they said to try
full throttle before pulling the plugs.

It worked but running the engine full power (near sea level) while leaned
for best power and peak EGT with minimum airflow for the minute it took
seems pretty abusive to me. Maybe you can get away with it because the
CHT's have not yet risen to max.

Any thoughts? What were you taught?