jetting

[The400exExorcist]

what pilot/main jet should i run in my 400ex?

wb e-series silencer w/ 4discs
k&n w/outerwear
440kit
airbox vents


thanks,
Eric

[Wheelie]

Why do you have only 4 discs in your E-Series? Try a 42 or 45 pilot and a 162-165 main jet. That might be too lean, but it should be a good starting point.

[The400exExorcist]

for some reason it feels like i get more bottom end with 4

[knighttime]

42 minimum on your pilot, and 160 minimum on your main. Good luck!

When you install larger jets you should be able to run more disks, what the other guys mentioned is a good starting point. Don't know too much about the 440 kits so can't help you out on which size jets.
John

[shook]

I have a 400 ex with a e series 12 disc's rev box and a K&N filter #40 pilot jet needle in the stock position and a 168 main with holes in my airbox lid about 10 3/4 in. towards the rear of the air box lid to keep the water directly off filter.I also run an outer wears on filter. Imchanging the pilot to a 42 and the main sounds big but if I dop back to a 165 you can feel a difference and this bike runs well for a stock 400.The 4 disc thing will give you more bottum end but that 440 needs to breathe you should be running something like 12-15 open it up a little if it feels strong with the 440 kit with only 4 discs its a good chance your lean. The four discs are stopping the bike up and richens it. I only run keihin jets get rid of those Dyna jet kits if you have one.More than likely if you put 12 to 15 discs in it and run a bigger main and pilot youll notice a power gain go up in main until acts as if the choke is on then drop back.