KIPS powervalve

Ok, so I have a Hyosung 250 '07 (carby). Riding to university the last few times (once on the motorway), the engine just stops. Nothing. Tach reads zero, speedo reading 20, 60, 90 kph each time it died. No problem, just push the starter and off we go down the road again. You get used to this sort of thing after a year with the Hyosuck. My guess is faulty stand sensor. Read up on KB that someone had similar issues. Dealership said it was chain grease on the sensor. The other day I took it off, cleaned ...