Q. Why does my 2018 KTM duke 390 cut out when I slow down?

Hi Brian, what do you mean by the term “cut out” ? Does the engine stalls or it doesn’t respond ? If that is the case then you need to visit the service center.If you don’t mean engine stalling or shut down then your answer is that Duke 390 has a very High Compression Engine. Hence whenever you slow down from a very high speed, you have to select the gears and clutch release ratio accordingly. It has to be in conjunction of the selected gear. Try practising it. If still you feel the same. You should visit the service center and ask the professional to ride the bike at your desired speed where you are sitting as a pillion and ask them to slow down to reproduce the issue. Check if it’s still happening. Ask them to repair the same. If they say that it’s normal then it’s okay.

This could be due to the lower initial RPM setting. We would suggest you to get in touch with the nearest authorized service center and they would be able to assist you with the details. Follow the link and select your desired city for service centers.

It maybe because of not changing gear to a lower gear while slowing down. if you are following the gear pattern then it might be the problem with the injector and combustion.