VIDEO: 850 Switchback Assault 146 Spark Plug Inspection and Replacement
Always wear safety glasses and nitrile gloves when servicing your Polaris snowmobile. To inspect and replace the spark plugs on your Polaris Switchback Assault 146 with an 850 engine, follow these steps:
1. Park the sled on a flat, level surface.
2. Remove both side panels by turning the three quarter-turn latches. Pivot the panels away from the sled and pull out to remove.
3. Disconnect the two hood latches.
4. Lift the hood up slightly to gain access to the connector underneath.
5. Disconnect the connector and remove the hood from the sled.
6. Carefully remove both spark plug leads.
7. Clean the area around the spark plug to prevent debris from falling into the engine.
8. Remove the spark plug wrench from the spark plug holder.
9. Use the spark plug wrench to loosen the two spark plugs and remove from the vehicle.
10. Inspect the electrodes for wear and carbon buildup.
11. Inspect and adjust the spark plug gap if needed. The gap should be 0.027 inches (0.7 mm).
12. If necessary, replace with the recommended spark plug. The spark plug is NGK BPR 9ES, which is part number 3022082.
13. Install the spark plugs into the engine. Torque to 18 to 22 ft-lbs (24 to 30 Nm) with a 13/16-inch crowfoot wrench.
14. Reinstall the spark plug leads and ensure they are secure.
15. Reinstall the spark plug wrench in its holder.
16. Reinstall the hood panel, ensuring the tabs in front are properly engaged.
17. Reconnect the connector underneath and verify it is secure.
18. Continue by securing the two hood panel latches.
19. Reinstall both side panels by inserting the upper tab and pivoting in to engage the lower tab.
20. Latch the three quarter-turn latches to secure each panel.
21. Finally, start the engine to ensure proper operation.
For more information, see your authorized Polaris Dealer. To find a dealer near you, use the Dealer Locator.
Maintenance tips, procedures and specifications can be found in your Owner's Manual.
To find diagrams and replacement part numbers, use the online parts catalog.