PDA

View Full Version : 400ex to 426 jetting



shortzt.15
09-19-2012, 12:01 PM
Ok so i just had the valve seals go outta my 400ex, so i toree it down and had to go big bore ect, any wasy i want to know what my jetting should be on a 400ex carb my quad has this done to it
426 10:1 wiseco piston
Stage 2 hot cam
Fmf porecore
k&n high flow with precharger
Also runningthe stock header but i have ground the welds out of it,
so any sugestion on how the carb should be set up?

DragonGunner
09-19-2012, 02:13 PM
Things to consider is temperture, an elevation. This time of yr. here in Indiana at 750 ft. I would start at around a 165 main, I also like a 42 pilot for easier cold starting. I run K&N with pre filter an open airbox so I run a 180 main with good results.

shortzt.15
09-19-2012, 03:26 PM
I'm at 919 ft and what about clip position and a/f screw also I'm running a closed airbox

hocman123
09-19-2012, 03:30 PM
3rd notch from the top on the needle thats the stock spot so it should be there allready and a/f should be 2 1/4 -2 1/2 turns out

shortzt.15
09-19-2012, 03:35 PM
Ok thanks and were can I buy the pilot jet at

hocman123
09-19-2012, 03:40 PM
well if u have a local dealler they should have it but if not this is the best site for jets http://www.jetsrus.com/

shortzt.15
09-20-2012, 09:32 AM
Ok well I have a dynojet jet kit in the carbon right now tuning dynojet main with the adaptor to run the dyno jet jets, do u digest tuning all kiehin or is dynojet ok?

CJM
09-20-2012, 09:54 AM
The dynojet will be notoriously hard to tune as thier jetting isnt very exact and the numbering system they use isnt even close to a keihin jet.

Stick to keihin jets, it will make your life much easier.