Removing airbox lid, stock bike

[MaTT400KfX]

Hi,
I want to remove the airbox lid and put a panty hose to keep my airbox a bit cleaner, because i ride in really dusty condition.

The bike is completely stock except noss machine adapter with Uni air filter, at sea level and temp is about 65-75 F. Do you think it would be a good to start with a mikuni 140 main jet? or i should try a bigger one to start , like 142.5 ?

And do you think that panty hose is good or i should really buy an outerwear to cover the airbox ?

[YFZ450Ridr]

i took my dads completly stock 2004 z400 and added a uni filter, took off the airbox lid, put an outerwears on the fiter(which you can get for like 10 bucks), and put in a 175 main jet and its jetted PERFECT. gave it gobs of torque and better throttle response. the jetting might not be exact for you because of different sea levels(im in st. louis) but id start with atleast a 165.

i wouldnt use panty hose, just doesnt seem right. outerears are cheap and work great. water resistant, catches lots of dust and dirt. you can order one from any place that sells atv parts for the most part.

[MaTT400KfX]

eh, are you talking about mikuni or dynojet, because a 175 mikuni isnt too big???
a 140 mikuni would be around a 150 dynojet if i'm not mistaken.

[YFZ450Ridr]

ya im talking about mikuni jets. heres a chart that shows whats equal to what

Mikuni--Dynojet
140-----149.3
150
142.5---152.0
145-----154.7
155
147.5---157.3
150-----160
152.5---162.7
165
155-----165.3
157.5---168.0
170
160-----170.7
162.5---173.3
175
165-----176.0
167.5---178.7
180
170-----181.3
172.5---184.0
185
175-----186.7
177.5---189.3
190
180-----192.0
182.5---194.7
195
185-----197.3
187.5---200
190-----202.7

[MaTT400KfX]

you put a 175 mikuni main jet on a stock bike with only the airbox lid remove? Seem to me way to big. Maybe i'm wrong, but i'd like to know if anyone else has suggestion.

thanks LTZ400ridr

[Titanium]

Originally posted by MaTT400KfX
you put a 175 mikuni main jet on a stock bike with only the airbox lid remove? Seem to me way to big. Maybe i'm wrong, but i'd like to know if anyone else has suggestion.

thanks LTZ400ridr

i agree. i'm running a 165 main jet and thats with a new headera and muffler and a k&n air filter with the airbox lid off.

[indyZrider]

every other chart i have seen like that has been reversed. the mikuni's were always bigger than the dj's. you got me curious now!

[YFZ450Ridr]

well i can assure you guys that my dad is running a 175 main. uni filter and no airbox lid. i ordered it all at once and put it on myself and it runs like a champ. no blubbering, spitting or sputtering. jetting is spot on with the stock needle, pilot jet and a 175 main.

[rmz250]

Originally posted by LTZ400ridr
well i can assure you guys that my dad is running a 175 main. uni filter and no airbox lid. i ordered it all at once and put it on myself and it runs like a champ. no blubbering, spitting or sputtering. jetting is spot on with the stock needle, pilot jet and a 175 main.

Its way to rich. Trust me, I've done alot of work w/ these carbs and people with full exaust and no lid are running lower than that.