Guys ,
Bog standard MC21 which starts and runs really well but noticed today that the 2 exhausts have quite different characteristics.

Today on a paddock stand at tickover, the right hand lower cylinder exhaust runs warm , popping nicely with quite a bit of back pressure just how I would expect one of my old single cylinder motocross bikes to run .

The left hand upper cylinder one runs really cool , even at full running tempereture , doesn't seem to make hardly any noise or back pressure and smokes slightly more , but things even out instantly with a few revs.

Is this normal for an NSR or is it a case of ' There may be trouble ahead' ?

Thanks in advance