Plugs last way longer than in days of old BUT if you have an alloy head, it is wise to unscrew and re -torque every year, otherwise they can become stuck in the head and could possibly lead to major surgery to remove.

Doug
2011 Plus 4 in Rich Maroon

1972 750 “ComDom” sprinter
1958 Triton 650
1992 Triumph Trophy 900