Q: I have a PA-25-260 ag plane. When I let it idle 640 rpm, it makes a popping noise, however after takeoff, when I reduce power (slowly), the loader says he can hear a popping noise.
Both mags check good and I recently replaced the spark plugs due to a drop in one mag. This fixed the mag problem. A day after I replaced the spark plugs, one mag sounded rough, which caused my mechanic and I to pull and look at the bottom plugs. Several already had lead forming. Cleaned, no problem. [Read more…]