Jetting help

[tws_andrew]

I am helping a friend setup his stock 450 R. On Sat we added a 13t sprocket, K&N filter and a Yosh full system. Bike is much better but I need jetting help. We are at about 4400 ft elavation. When I we removed the airbox lid the bike would not run at all so I assume it went way too lean. We got a K&N Jet kit from Rocky Mountain. The bike is mainly ridden in the sand. Any recommendations for jetting? Also where is the fuel screw on this bike? Thanks for the help

[Mobile Dyno]

What jet size do you have in know?

[tws_andrew]

Stock. Didn't have time to change. Runs quite well with this setup but I know there is more in there with the lid off

[Blown 331]

Start by ditching the lid and going with a 185. That should be ball park.