225dx carb jetting for aftermarket exhaust

[motoman011]

I am purchasing a dg exhaust for my sons 225dx, any ideas on jetting and such would be a great help stock jet sizes are as follows

main - 112.5
pilot jet - #20
air screw - 1 1/2 turns out

Hopefully I can just change the main jet and make adjustments to the air screw and be good but any help will be greatly appreciated

[Yamaha_Rules69]

You may possibly not have to re-jet at all. Put the pipe on, and see what it does. Do a plug chop, to see if it is running lean (white color) or rich (black color) You want to have the plug a light to medium brown. If you do end up jetting it, I would see you going one or two sizes bigger on the main, and leaving the pilot alone. In colder weather, like winter riding, it should be jetted a little fatter, so keep an eye on that as well, and good luck!