Seem engineering and QC are below Japanese standards. Fleet reliability is spotty with many going for years without problems, while other are constantly in shop.
https://www.motorcyclistonline.com/l...-final-update/
BTW, Ari Henning set Lightweight Twins record at Sears Point Sonoma on RC390
Lots of reports all over forums like this:
https://www.rc390-forum.com/threads/...t-louder.1092/
https://bayarearidersforum.com/forum...d.php?t=500624