WB E-Series cold weather jetting

[Jimford]

When I install my pipe will the cold weather effect performance when I rejet? Should I buy a couple different sizes to try out? What size main and pilot should I use? I live in Buffalo, New York and it is in the 30's here and getting colder!

[cals400ex]

what kind of bike?
what is the elevation your at?
what are ALL of the mods do you have done?

[Jimford]

Sorry man. I have a 99' 400ex. No mods except uni filter. I really don't know the elevation. Whatever it is in New York. It is probably the same as ohio. I appreciate any help, thanks!

[cals400ex]

i assume you run an airbox lid on. the elevation and temp really make a difference. with just the uni and slip on silencer, i would TRY a 155 if it is getting pretty cold. i would probally run a 152 in the warmer months. go ahead and just buy a 42 pilot jet. that will work in the warmer and colder months.

when you buy new jets, make sure you buy keihin 13 series mainjets of the sizes you want (152, 155, etc)
when you but the new pilot jet, make sure you buy keihin 21 series pilot jet of the size you want (42, etc)

good luck. yes, jetting will make a little difference. it will also be better on the bike so your not running it too lean.

[flying400ex]

hey i have this fatboy 4 and i am trying to get the jetting right. I am at 800-1000 foot above sea level its around 40-45 degrees out I dont run an airbox lid and i have a filter but thats it, i was wondering what you guys thought. I have a 155 main in right now and it runs ok but it cracks a bit and backfires a little coming down from WOT oh and my headers are kinda glowing am i too lean?:)

[cals400ex]

Originally posted by flying400ex
hey i have this fatboy 4 and i am trying to get the jetting right. I am at 800-1000 foot above sea level its around 40-45 degrees out I dont run an airbox lid and i have a filter but thats it, i was wondering what you guys thought. I have a 155 main in right now and it runs ok but it cracks a bit and backfires a little coming down from WOT oh and my headers are kinda glowing am i too lean?:)


your main jet should work fine, i probally would go down a size, but a 155 will run fine. with the airbox lid off i would probally move the clip on the needle from the stock 3rd position to the 4th position. also, put in a 42 pilot jet. yes, your too lean if your headers are glowing. if you move the clip in your needle like i said and put in a 42 pilot jet, the headers shouldn't glow. let me know if you have any other questions.

[flying400ex]

ok i am going to go out and try that

[flying400ex]

ok now i am pissed.... i put a 168 main in because i am told to run a 165 with the pipe with an air filter and no lid. i used the 168 because it is a bit colder. Now it wont run with the choke off and i keep getting a backfire almost like a sucking sound or a blowing sound come back through the carb and i am seeing the carb kinda knock forward and back in the carb boot. Maybe cause i am testing it with very very little gas in the tank but it doesnt seem that would be the case. I need some help please! Oh i turned the air/ fuel screw on the bottom of the carb in 1 turn and then i tried out a turn and it didnt seem to help either way really except it ran a slight better with it turned in.:mad: :mad: :mad: :mad: :grr:

[flying400ex]

bump

[cals400ex]

ok, i didn't realize you had the pipe on now. i would run the 152 or 155 with the stock pipe. with the fatboy, try a 158 or 160. however, i am not sure what your problem is. what exactly did you do to your bike in order for it to not run?? did you just change the mainjet or did you mess with the needle too? it sounds like you have an air leak. make sure the carb clamps on on there tight.

[400ex#18]

if you are running a wb, i would use the 155 main, and not touch the pilot, i live like a few hours away, so it is pretty much the same. a 155 with the air-fuel screw 3 turns out. that means screw it alll the way in and then go out 3 turns, leave your lid on, and try that, let me know. i used to have the same problem.

[adrenaline]

i have a wb bros pipe on i live on long island so there really is no elevation..but i was told to take the choke out and install the 42 pilot jet and main jet to 155..im trying to learn more about this so any advice helps me out a lot..thankyou

[adrenaline]

oh i forgot temp...this weathers been crazy..it goes from 20ish-55ish lately but im asuming winter conditions 20-35degrees...also what would you recomend for summer riding 70-90degrees..i also travel to Pa to ride with some friends is this jetting alright for that elevation..lets say 2000feet

[cals400ex]

Originally posted by adrenaline
oh i forgot temp...this weathers been crazy..it goes from 20ish-55ish lately but im asuming winter conditions 20-35degrees...also what would you recomend for summer riding 70-90degrees..i also travel to Pa to ride with some friends is this jetting alright for that elevation..lets say 2000feet


i change the mainjet about 3 times a year. you might need a 152 in the really hot months and you might need a 158 in the really really cold months. as you get higher elevation, you decrease the size of your jets. with it being 2000 ft difference, that may be one jet size.

[adrenaline]

thanx