Dr. D pipes

[trxkruzoffman]

on the Dr. D web page it says that there is no jetting required for the slip on pipe. so does this mean that u can run stock jets when u get the Dr. D?

[04TRX400EX]

You could stick with the stock jetting, but it won't run that well. I just put my Dr. D on a couple of weeks ago along with a K&N and ran ok, the spark plug was still an ok brown/tan color too. The quad felt like it was starving for fuel though. It wasn't crapping out or anything, but then I changed the main from stock 148 to a 150, and it made a world of difference. It's easy as pie to change the main jet on a 400EX. If you get a pipe, see how it runs. Maybe you'll be fine, but your probably have to re-jet.