UNI Filter and jetting

[400exquad]

I've got a stock 400ex that I'm about to put a UNI filter in, and would appreciate any advice on jetting for ~700ft. , air box lid (no holes), 80 - 90 degree temps.

I was thinking I might start out with a 152 main jet, and maybe a 40 pilot? Or Would I be ok just richening with the pilot screw, and stock 38 pilot? Thanks!

[300exTJjeeper]

go 1 up on the pilot bump up the clip on the needle and about 2 sizes up on the main.

Go from there and fine tune the motor. It will proably be alittle rich but it will get you in the ball park.

another thing. Leave the pilot 1 up and just mess with the main. And youll be fine

[White_Knuckles]

Just the addition of a UNI with no airbox or pipe mods you should only go 1 size up on the main. If air temp and altitude permits and your current jetting is on the lean side 2 sizes. The pilot (idle) circuit should be fine, maybe a half turn out on the fuel screw. No need for a larger pilot jet.

Just a UNI won't effect jetting much if at all. Come on, get the slip-on and open up the airbox, that's when the "feelable" gains awake.


:devil:

[TRX_Thumper]

yeah i put a uni on mine and for me there wasnt any need to screw with the jetting

[400exquad]

Originally posted by White_Knuckles
Just the addition of a UNI with no airbox or pipe mods you should only go 1 size up on the main. If air temp and altitude permits and your current jetting is on the lean side 2 sizes. The pilot (idle) circuit should be fine, maybe a half turn out on the fuel screw. No need for a larger pilot jet.

Just a UNI won't effect jetting much if at all. Come on, get the slip-on and open up the airbox, that's when the "feelable" gains awake.


:devil:

I told myself I wasn't going to get a pipe when I bought this thing. I can see that lasting about another month :D I'm sure I'll be searching the forums sooner than I'd hoped to figure out what pipe to get...

Thanks again everyone for the suggestions! I'll let you know how it goes.

[Woodsrider]

Originally posted by TRX_Thumper
yeah i put a uni on mine and for me there wasnt any need to screw with the jetting

Same here. I ride everything from 0 to 4500 feet and withthe uni by itself I didnt have to mess with the jetting, I'll be getting a E-series slip on next month along with a couple other things, then I'll definatly have to rejet;)

White Knuckles, where in the Northwest are you at?

[Chanman420q]

i didnt rejett for my UNI.........

[cals400ex]

i say 152 is too big for just the filter. that is what i was running when i had no air box lid and a gutted factory pipe. the stock main jet is a 148. i would just put in a 150 since the bike is a little lean from the factory anyways. i would put in a 40 or 42 pilot just since the 400ex is hard to start in the first place. as for the needle, i would either leave it in the 3rd position(stock) or go to the 4th.

[300exTJjeeper]

ok forget the clip just go 1 up on the main and 1 up on the pilot. For way easier starts no need to use the choke. with a bump up onthe pilot