OEM Mercury Montego Spark Plug

Mercury Montego Spark Plug Parts and Q&A

• Spark Plug
  AGSF-32W-MX
  Q: How to inspect a spark plug for issues such as bridged gaps, fouling, and overheating on Mercury Montego?

  A:

  Check the spark plug for bridged gap dangers and evaluate the electrode deposit accumulation to determine if it has caused the gap to close because of oil or carbon fouling. Clean the spark plug when the condition requires cleaning. Before putting in a new spark plug check for oil fouling through black wet deposits on the insulator shell bore electrodes which gets there because of excessive oil entering the combustion chamber because of worn rings, pistons, or excessive valve-to-guide clearance or worn or loose bearings. Fix any oil leak before installing the new spark plug. The presence of black dry fluffy carbon deposits on insulator tips and electrodes and shell surface areas necessitates new spark plug replacement because these symptoms could be caused by improper heat ranges and air filter filth or too-rich fuel mixtures along with prolonged idling. Examine the firing tip for normal burn appearance because light tan or gray-colored burn deposits signify proper functioning. The combination of melted electrodes and damaged insulators shows pre-ignition along with engine damage that stems from wrong ignition timing or improper fuel use or unauthorized hell-coil thread inserts require installing a new spark plug. Look for overheating symptoms which include white or light gray spots and a bluish-burnt appearance of electrodes from engine overheating, wrong fuel type, damaged spark plugs or those with improper heat range and low fuel pressure and incorrect timing. Replace the spark plug if needed. Particularly inspect fused deposits which manifest as melted or spotty bubbles that usually form when accelerating sharply then check for replacements.