Forums 🚥 PiT STOP 🔧 Hyosung Technical Help ST7 (GV650) F1 light due to clutch lever switch ???

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    • #13817
      • Topics: 3
      • Replies: 12
      Penrherber, Cymru

      Greetings all.

      A nice morning ride was spoilt somewhat today by the ST7 engine cutting out and the red F1 light coming on.

      After a min or so it re-started but repeated the cut out 4 times after this before I got home (about 6 miles). I was doing around 60 at the time of the original failure.

      I noticed that when it cut out if I pulled the clutch lever in it would restart straight away. Could the micro switch be playing up ? Is that contact only needed to be right for the starter motor to work, or can it effect the running engine.


      The stator etc have been replaced long ago and I have a voltmeter fitted which shows 12.5 to 13.8 with the engine running. The fuel pump makes it’s priming swish noise when the ignition is switched on. No signs the engine is overheating. The F1 light goes out once the engine is re-started.


      Any ideas welcome.


    • #13828
      ♠️ MARCEL
      • Topics: 45
      • Replies: 1,892
      North UK

      Hey Steve,

      Clutch Switch will cut sparks off anytime if it plays up, I’ve experienced this myself more than once on my GTR bikes , so much so , that even today we have had 2 orders in wales & dorset for clutch switches to be sent for GTR bikes.

      It would be wise to replace it and get 2 of them (1 for spare) , if your local dealer can’t help , just email us.

      Keep in mind, ST7s have longer bars than GTs and GTR’s , so don’t try to use their switches as it simply will be 50% too short!  – Some terminals may change too!

      I would not recommend bypassing it,  as fake neutrals “can” happen , so you want to guarantee yourself the clutch is squeezed in before starting.

      Also it is very important the side stand switch is Bypassed! (the most annoying object on the bike!) ,  bridge the wires , and tape it very hard so there is no chance of water invasion , lest it rots the wire and you’re back to square one.



      Regulator = I pray the regulator is actually doing 13.5 during idle  and 14.5v during 5k revs  , otherwise , time to upgrade to shingdens!  (Like this one) , the stator too.

      Carb bikes can get away with a poorly reg / stator for a short while, but EFI bikes are power thirsty  (with zillion sensors all over the place with a fuel pump that draws a lot of amps!) , you want to make sure the charge system is future proofed.  Less costly than replacing a delicate fried ECU and ST7 ECU’s are too difficult to buy.

      // Meditation doesn't mean you have to sit still....

    • #13832
      • Topics: 3
      • Replies: 12
      Penrherber, Cymru

      Thanks Marcel.

      The good news is when connected to a digital (in other words accurate) voltmeter I’m getting pretty much what you describe, though of course the ST7 has no tacho so I just give it a good rev 🙂


      I’ll send you a message re a replacement switch.


      My side stand switch failure was involved in my 3mph crash a year or so ago and was promptly removed from the circuit.


      Regards, Steve.

      • #13977
        • Topics: 2
        • Replies: 9

        Safety us to death. It is mostly what we work around. Well, that and emissions. Some safety devices are warranted ( if you rise off the seat of your tractor).

        Side stand switches will cut the ign. just as you realize it’s down and folding up= no speed dump to the ground. Oddly my 2019 Tacoma has a clutch override switch- you can bet I double-check for neutral if outside the truck.

        If they quit teaching us all there is no common sense.

        Marcel you remind me of FOG fast old guy from  Ninja 500 forum days .


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