The following instructions are based on the DCS6400, DCS6401, DCS6420, DCS6421, DCS7300, DCS7301, DCS7900, and DCS7901 model Makita chainsaws. Always read and be familiar with your equipment's operator's manual to understand the specific parts and procedures that pertain to your equipment.
Never touch the spark plug or plug cap while the engine is running. Make sure you turn the engine off and allow it to cool before attempting to service your equipment in any way. Wear protective eye and hand gear while performing maintenance.
Only use an NGK BPMR7A spark plug for the models listed above.
- Step 1: Turn off the engine and allow it to cool before beginning to work on your equipment.
- Step 2: Take the filter cover off.
- Step 3: Remove the spark plug cap from the spark plug.
- Step 4: Use the combination wrench supplied with your unit to remove the spark plug.
- Step 5: Replace the spark plug if insulator or electrode is excessively worn or damaged. If the electrode is very dirty or covered in oil, the spark plug should be replaced.
- Step 6: Check to make sure the electrode gap is .020'' (0.5 mm).
- Step 7: Set your combination tool between the head and the cylinder but not in the spark plug hole. Make sure it is only touching the cylinder.
- Step 8: Attach the spark plug cap to the unscrewed spark plug.
- Step 9: Hold the plug with insulated pliers against the combination tool (away from the spark plug hole).
- Step 10: Switch the ignition switch and pull the starter cable briskly.
- Step 11: A spark will be visible near the electrode if there is proper functionality.
For information about safety, warranty, and your specific model, read and be familiar with your owner’s manual.