what size jets do i need for a 00 honda 400ex with 440 big bore kit and stage 2 hot cams and full exhaust

maverick4925 · 07-12-2011, 06:00 PM

i'm boring out my cylinder .020 and i have an hmf slip on. i know before i did the bore kit that the carb never got jetted for the slip on so i'd like to hear from you guys what jet sizes i should get and where i should get them.

TRX2fiveO · 07-12-2011, 06:05 PM

What size quad and year?? .020 is like 1/2 mm over stock plenty of meat left for future work.

maverick4925 · 07-12-2011, 06:11 PM

it's a 2004 400ex. but i'm only doing 20 over because i dont need to much power yet. still a beginner. never ridden a motorcycle or a quad, and i only rode my quad 2 times for about 10 miutes a piece.

DAN400ex · 07-12-2011, 06:44 PM

For a slip on and (I assume the .020 is what, a 426?), if thats all your running probably a 160 main jet, what do you think moose, 42 pilot? Now if your running an open airbox lid you’ll want to run a 175. What other mods do you have going? Dyno jet makes good kits, I’m very happy with mine. However, if you want to buy individual jets rockymountainatv/mc.com sell them but if you want to go that way you’ll need a 175 to 177 main jet for just the bore kit and slip on, and if your running an open airbox lid you’ll want to go with a 192 to 195 main jet, reason being that keihin jets and dyno jets are sized differently.

TRX2fiveO · 07-12-2011, 07:53 PM

Quote:

Originally Posted by DAN400ex

For a slip on and (I assume the .020 is what, a 426?), if thats all your running probably a 160 main jet, what do you think moose, 42 pilot? Now if your running an open airbox lid you’ll want to run a 175. What other mods do you have going? Dyno jet makes good kits, I’m very happy with mine. However, if you want to buy individual jets rockymountainatv/mc.com sell them but if you want to go that way you’ll need a 175 to 177 main jet for just the bore kit and slip on, and if your running an open airbox lid you’ll want to go with a 192 to 195 main jet, reason being that keihin jets and dyno jets are sized differently.

A 400EX is actually 398cc .020 is .5 over stock making it about a 402cc.
42 pilot is always good with a slip-on and filter 180 keihin hex without the lid 190 hex jet. dynojet would be roughly 160 with the lid 170 without

maverick4925 · 07-13-2011, 02:08 AM

Alright thanks for your answers. I don't have any other mods just the bore and slip on. But is there any difference in power with the open lid air box?

TRX2fiveO · 07-13-2011, 05:11 AM

Yes there is a difference. but you will have to clean your air filter more often.

maverick4925 · 07-13-2011, 10:12 AM

ehh that's alright. i can handle that. so how do i go about breaking this thing in when i get it rebuilt? and how can i tell if i neede a new timing chain? and how does that tensioner work? i just want to make sure i get it right.

TRX2fiveO · 07-13-2011, 02:06 PM

if you need a service manual look in the manuals and schematics section there is a free download there.

HOLY CRAP!!!! I sound like deeperinthebush...LMAO

Deeperinthabush · 07-13-2011, 02:12 PM

Quote:

Originally Posted by TRX2fiveO

if you need a service manual look in the manuals and schematics section there is a free download there.

HOLY CRAP!!!! I sound like deeperinthebush...LMAO

I heard that Meese,errrrr Moose...