Do lawn mower spark plugs need to be gapped?
Summary. Lawnmower spark plugs can come pre-gapped, but this depends on the manufacturer. However, in most cases, the gap can be too small or too big, which can lead to ignition problems. ... Spark plugs need to be pre-gapped to ensure proper ignition of the air and fuel mixture.
Furthermore, what should a lawn mower spark plug be gapped at?
Flathead Engine Spark Plugs & Gaps
|Replacement Part Type||Replacement Spark Plug Options by Briggs & Stratton Part Number||Spark Plug Gap|
|"Surefire" RJ2YXLE in Craftsman Smooth Start (MRS) lawn mower||591040||.030”|
|Replacement Part Type||Briggs & Stratton Spark Plug Part Number||Spark Plug Gap|
|Electromagnetic Suppression (EMS) (Replaces Champion QC12YC)||691043 792015||.030”|
|Extended Life Series® OHV Spark Plug Platinum (Replaces Champion RC12YC)||696202 5066 (5066D, 5066H)||.030”|
Likewise, people ask, what happens if the gap is too big on a spark plug?
One of the key factors that makes a spark plug work well, or not, is the size of the gap between the electrodes. ... However, if the spark plug gap is too large, the spark is unlikely to consistently "jump" across the long distance between electrodes, thus leading to a rough-running engine or one that doesn't run at all.
How do I know if my lawn mower spark plug is bad?
Here's How to Know if a Lawn Mower Spark Plug is Bad
- You can't get the engine to fire up at all.
- You have to tug extra hard for longer than usual on the rewind.
- Your lawn mower loses power while moving.
- The gas runs out quicker than it used to.