Switches & safety cut-outs

How it works

Switches are the bike's small safety and control switches: ignition switch, handlebar switchgear, side-stand switch, clutch switch, brake-light switches, neutral switch. Several form a safety chain: on many bikes the engine won't start, or cuts out, if the side stand is down with a gear engaged; some require the clutch pulled in; scooters often need a brake lever held to start. A dirty, corroded or misadjusted switch can therefore stop the engine starting, cut it while riding or leave the brake light on. The side-stand switch, mounted low and exposed to water and mud, is a frequent culprit. Diagnosis is done with a multimeter or by checking the safety logic in the manual. Replacing a switch is usually simple.

Maintenance tips

• ✓If the bike won't start, check the safety logic: stand up, neutral or clutch pulled in, kill switch on 'run'.
• ✓Clean the side-stand switch and its connector, which are very exposed to water and mud.
• ✓Check the brake light comes on with each brake, front and rear.
• ✓An engine that cuts out over bumps can come from the side-stand switch or a loose connector.
• ✓Never bypass a start-safety switch: replace the faulty one.