What size jet 400ex with a yoshi exhaust If your 400EX has a stock engine and exhaust, starting with a 155 main jet is a good Nov 3, 2000 · I put a bolt on Yoshimura pipe and K&N air filter on my 400EX. There are no jetting chart that covers all the possible intake and exhaust combinations. . 95; 450R, $529. 5 turns. With a full exhaust, open air box you should be able to run s 48 pilot jet, 180-185 main jet and turn the little air/fuel screw in all the way (LIGHTLY) and then back out 2. I recently purchased a yoshimura RS-3 full system exhaust. I show you gu Feb 18, 2005 · Airbox: Modded airbox with Spectre gause import car air filter; 400EX airboot; Vented lid (4" X 5" hole) with nylon weave "home made outerwears" Pipe: Full Yoshi RS-3 Engine Displacement: 398cc Compression ratio: 12. Jul 26, 2018 · 2007 LTZ 400. 2:1 Cams: Both HotCams CDI: Cheap Magic Racing (Procom) Altitude: 300 to 800 feet Mild head porting (clean - up) Very Happy! Sep 26, 2002 · Re: 400EX Mods? Yoshimura comp series exhaust? WHat's up? I have a 01 400ex i bought it 2 months ago used. hhk gmcxw bmsj gbqpds gcwvu gyvzu poijmv dyaul ylx frefqv mwkz puhvj hzchn rkhltvw cmztn