hi guys
me again have filled holes in collector box
on my nc21 with gun gum not blowing or popping now
sounds fine do till i get new box
on starting her up today a bit of blue smoke for
about 15 seconds or so then ok should this be something
to worry about hasnt done it again sounds fine no unusual noises
cheers

had the bike 2months now never done this before
is it because i filled holes in collector box
cheers

iirc then blue smoke is the sign of burning oil which could be from a range of things.

If it's only on start up and not whilst running, under load or when coming off load I wouldnt worry about it

Blue smoke is never great, it's generally rings or valve stem seals/guides.

IIRC, if it's only on startup, or start up and gearchanges, then it's likely to be seals, if it's all the time, then rings are the most likely culprit. Only on start up would be the least worrying, as it points to oil gathering when the bike is not running, and then getting burnt off on start up.

There is a small chance it's burning off excess oil if you have overfilled though - that's by far the cheapest fix, just empty some out!

Main thing is keep an eye on your oil level.