2007 TE 250 Big Bore

I'm getting ready to install an Athena 300cc kit on my 07 Te 250. Bike runs great right now.
Any advice on which direction to take my jetting. I've heard it needs to be richer but also that it needs to be leaner.

Anyone with real world experience on their big bore 300 te ?

I installed the Athena big bore kit on my 07 TE250 about 4 years ago. I had already installed the JD jetting kit when it was still a 250 and did not need to change the jetting at all. Bike runs great & the spark plug color is spot on. You will like the difference the big bore kit makes!!

Thanks for the response.

I know this a two year old post. Just ordered a Athena big bore kit for my 07 TE250. Can you expand on how it changed your bike?