Originally Posted by Crazy Canadian
Yes unless you want to run crazy lean and risk serious damage.
Maybe not, if your running slightly rich (unlikely, though that is) you may be fine without a re-jet.
My bike was running ok but some things you've just got to try.
I took the snorkel out & bike improved performance. Put the snorkel back in & the thing bogged & was unridable.
Mine has a mind of it's own!
Had to get a few jets & try them out.
Ended up going a smaller jet than stock. Plenty of km's since without an issue.
Mind you, it's generally warm & dry here.