how easy is it to just increase jet size without rebuilding. My carb works fine but since I put the header on I think I am running lean. (no cats either)

You probably are running lean.
It's easy to increase jet size. Just purchase the appropriate jets (Mazda Trix) and open the top of the carb. You'll need a tiny ratchet right-angle screwdriver, or you can remove the jet-changing plug bolts on the sides of the bowls and enter in that way with a regular screw driver.
Tweezers help.

Carl and I are always glad to help with any questions, but please don't hijack a "how-to" thread. Instead, just post a new one. That way the "how-to"s don't get so long and clogged with info that does'nt really help with the original topic.

Thanks.

mtrix has like 20 different sizes listed.. What size is appropriate for what? And what is the stock jet size? Also are their prices for 1 or for 4? You need 4 right?