Yamaha Warrior atv with aftermarket exhaust needs carburetor jets?

I bought a Yamaha Warrior with a Pro-Circuit T-4 exhaust on it. The person who had it before never changed the jets in the carburetor to accommodate the exhaust. The stock is 145, what should I upgrade to?|||It really depends on how smooth it is running, but often to get the maximum power out of an exhaust upgrade you do need to re-jet it. The easiest option is to simply get a K%26amp;N power-kit which will include a K%26amp;N filter and new jets. The best part about the power-kit is the detailed jetting instructions they will include which can save you a lot of hassle and waiting 1week for every jet you order at your local dealership.|||why don't you call pro-circuit and ask them.