Thanks MarkF12.
OK, I'll check guide.
But probably it is power valve, because I hear noise close to that during rev throttle on place,
during warming engine.
Will try to check this somehow...
Probably need to clear valve with axis...

Hi all,
few days ago got my CRM250AR from Japan.
Had a little ride after service, it's really mad bike, just what I wanted to get :-)

But I had some problems with quiet ride, when engine slows down,
and I try to ride on low turnovers, I hear some noise (knock), and feel some shock via frame.
Like ...