I have been dealing with a Random missfire on my 2016 Stelvio NTX for over a year. It started at around 12000km and went un-diagnose until 27000km. Poor idle, surging and hunting . I finally left it at the dealership with instruction that I didn't want it back until it was 100%. They thought It might be the idle Stepper motor and finally got approval from Piaggio to replace it. Upon disassembly to install the Stepper motor they discover a 1 1/2" hole in the airbox under one of the rubber tubes connecting the TB to the airbox with excessive dirt and sand in the airbox. So the Tech checked a 2016 Stelvio sitting on the show room floor and guess what, same hole same location. They checked another customers 2016 Stelvio in for service and it did not have the hole so its not a consistent defect.
(Now I had noticed excess sand and dirt in the airbox when I serviced the Air filter at 15000km. and let the dealer know, I was told I likley didn't get the airbox sealed when I last check the filter. So I replaced the Airfilter and made sure the airbox was sealed correctly.)
Anyway there had been so much dirt passed through the throttle bodies that they where worn out and would not seal when closed. This would explain the hunting and surging as the stepper motor was trying to compensate for the extra air present on the TB side of the filter.
Once the Throttle Bodies had been replaced and the hole patched Stelvio runs and idles as it should. I have requested extended warranty from Piaggio and they are dragging their heals. 11 emails so far back and forth and still nothing yet.
Common sense would dictate that if there was enough dirt passed through the TB that they wore out .... That dirt also went through the motor!
I still think the Stelvio is a Great Motorcycle and Love it but I have to say I'm not impressed with PIAGGIO!
will post and update when I hear back
(Now I had noticed excess sand and dirt in the airbox when I serviced the Air filter at 15000km. and let the dealer know, I was told I likley didn't get the airbox sealed when I last check the filter. So I replaced the Airfilter and made sure the airbox was sealed correctly.)
Anyway there had been so much dirt passed through the throttle bodies that they where worn out and would not seal when closed. This would explain the hunting and surging as the stepper motor was trying to compensate for the extra air present on the TB side of the filter.
Once the Throttle Bodies had been replaced and the hole patched Stelvio runs and idles as it should. I have requested extended warranty from Piaggio and they are dragging their heals. 11 emails so far back and forth and still nothing yet.
Common sense would dictate that if there was enough dirt passed through the TB that they wore out .... That dirt also went through the motor!
I still think the Stelvio is a Great Motorcycle and Love it but I have to say I'm not impressed with PIAGGIO!
will post and update when I hear back