[Wreckless_Rider]

First off im new to the site, but not to the atv world. Just got this 2000 400ex that needed full rebuild, so ended up doing stock bore size Wiseco 11:1 high compression piston, fully ported head, ground the welds on the stock header, white brothers E series slip on, k&n filter, no lid, rev box, and a hotcams stage 1. Bike has jetting at 170 main and 42 pilot, not sure how its going to run. Elevation 69' above sea level. Was wondering if someone could give me a good round about on where the jetting should be with all the mods being done.

 

[SlammedRanger]

Welcome to the forums! My buddies build is very similar. Minus the cam and rev box. But stage 1 cam isnt gunna make much of a difference. I have his quad at 180 main and 42 pilot mixture screw at 2 1/2. Our elevation is 760 above sea level. Shouldnt be enough to really effect anything there. My .02

 

[Wreckless_Rider]

Thanks! Yeah i figured i might have to bump up the jetting a size or 2. It was at 170 main 42 pilot before it blew, it had stock piston, no port job, stock header unmodded, and stock cam. It did have the slip on already and k&n filter with no lid. I know rev box wont make a difference.

 

[tennrider24]

I have a stock bore and stock carb, stage 2 hotcam with CRF 450r chain, aluminum airbox with vented lid, K&N filter, slip on HMF pipe, and big gun CDI rev box. What jets should I be running?

Thanks

 

[SlammedRanger]

I have a stock bore and stock carb, stage 2 hotcam with CRF 450r chain, aluminum airbox with vented lid, K&N filter, slip on HMF pipe, and big gun CDI rev box. What jets should I be running?

Thanks

What size vents did you put in the airbox and how many? Honestly your pipe and cam wont make a huge difference without enough air coming into the engine. And that is also going to effect your jetting. I highly suggest removing the lid or getting a outerwares cover for a lid if your worried about mud getting in. Which the vents let in mud and water anyway. My .02

 

[tennrider24]

You got Facebook? It's easier to send pictures of it on there. Logan Hunter

 

[SlammedRanger]

No i dont have a facebook sorry.

 

[SlammedRanger]

Haha never would have though i would get 2 likes from saying i dont have a facebook lol thats just funny!

 

[tennrider24]

This picture shows the vents in my airbox, with a K&N Filter, HMF slip on, Stage 2 hotcams, and Big Gun CDI rev box. Any idea for jetting?

 

[SlammedRanger]

Thats gunna be as open as no lid honestly. I would bet your gunna be around 175-180. I would get a 170-175-180 and try each one. That and a 42 pilot jet and you should be good to go. Make sure you only get genuine keihin jets. I usually order mine from jetsrus.