What is the spark plug gap on a Mercury?
Spark Plugs for Mercury and Mariner TwoStroke Outboards
| Model | Country | Gap |
|---|---|---|
| 4.5 (45)(1 cyl.) | CAN | . |
| 5 (1 cyl.) | USA | .040 |
| 5 (1 cyl.) | BEL | .040 |
| 6 (60) | USA | .025 |
How tight should outboard spark plugs be?
Tighten the spark plug finger-tight until the gasket reaches the cylinder head, then tighten about ½ – ⅔ turn more with a spark plug wrench.
What brand spark plugs does mercury use?
NGK spark plugs
NGK spark plugs come from the factory pre-gapped for your Mercury outboard.
What is a surface gap spark plug?
This surface gap style plug positions the spark approximately 1/16 inch into the combustion chamber with no exposed ground electrode. This helps expose the spark to the mixture and protects against pre-ignition from an overheated ground electrode. Note: The surface gap style runs too cold to burn away fouling deposits.
Can you over tighten spark plugs?
Over-tightening a spark plug in an aluminum cylinder head can entirely damage the spark plug thread, requiring spark plug replacement. So the best solution is to use a torque wrench and follow the recommended torque mentioned by your manufacturer.
How many spark plugs does a HP Mercury outboard have?
two spark plugs
PRO TIP: There are two spark plugs on a Mercury 20HP 4-stroke outboard, and it’s important that the cables are attached to the correct spark plug. Label each cable before removing them both, or remove one cable, and replace that spark plug and its cable before working on the other spark plug.
What is the recommended spark plug gap?
between 0.020 and 0.040 of an inch
For most racing applications, you usually want the plug gap to be between 0.020 and 0.040 of an inch. Most engine builders seem to settle around 0.035 of an inch. Factors such as the type of ignition you run, cylinder heads, fuel and even timing can affect how much gap will work best for you.
What are the different spark plug conditions?
What A Spark Plug Can You About Your Engines Condition
| Condition | Clues |
|---|---|
| Normal plug | Brown or grayish- tan deposit on side electrode, |
| Carbon-fouled plug | Black, dry, fluffy soot on insulator tip and electrodes. |
| Oil-fouled plug | Wet, black, oily deposits on insulator tip and electrodes. |