What is the purpose of this connection?

[oliverw]

Hi there!

I am a new owner of the magnifique Yamaha XS400.

Unfortunately the bike is hesitating when I rev during running.

With neutral and/or clutch down while driving I can rev freely.

 

[drewpy]

that's the brake light switch.
sounds like its bogging down under load. check ignition timing, spark plugs and fuelling

 

[oliverw]

that's the brake light switch.
sounds like its bogging down under load. check ignition timing, spark plugs and fuelling

The brake light switch where the clutch is?

 

[CaptChrome]

Other side is the clutch switch which tells the starting safety circuit that it is ok to spin the starter with the bike in gear as long as the clutch is pulled in.

 

[oliverw]

Other side is the clutch switch which tells the starting safety circuit that it is ok to spin the starter with the bike in gear as long as the clutch is pulled in.

Okay, thanks for the information

 

[GuyS]

Yup. Newer clutch/safety switches are available. But it is really just a simple serial switch. There’s no IC’s or complicated circuits