which jets do i need

[f150mann]

hey guys, i have a 01 400ex, i was told then i got it (not sure) it had stage one hot cams and a uni filter, i checked and i do have a uni, also a hmf sport series pipe, and the airbox lid is on, what jetting do i need to order??

[JOEX]

Originally posted by f150mann
hey guys, i have a 01 400ex, i was told then i got it (not sure) it had stage one hot cams and a uni filter, i checked and i do have a uni, also a hmf sport series pipe, and the airbox lid is on, what jetting do i need to order??
Using stock style jets a 150 or 152 main should be good but you might want to get a 155 too. A 40 pilot may help if you have difficulty starting.

Air temperature and elevation will play a roll in selecting the correct jets.

[f150mann]

really just stock jets??? that seems odd.

it starts easy now, i dont usually have to choke it

[CarGuy7a]

Originally posted by f150mann
really just stock jets??? that seems odd.

it starts easy now, i dont usually have to choke it

he's talking about STOCK STYLE jets. Kehin brand jets. they make them in all kinds of sizes.

[JOEX]

Originally posted by CarGuy7a
he's talking about STOCK STYLE jets. Kehin brand jets. they make them in all kinds of sizes.
Exactly, as opposed to the jets found in most 'jet kits'.

The kits have a different numbering system, require an adapter for the main jet and the use of the needle that comes in the kit. They don't include a pilot jet either.

You shouldn't have pay more than $5.00 for a jet...

[f150mann]

sorry dont know much about jetting..something i hate to get into, so ill ask for a stock styled jet, 152 main and 40 pilot?

[Ry007]

I posted an article about jetting a few days ago. Look at it, it was about the pilot jet. As for your specs. I don't know the altitude, but it says on my dynojet Instructions (that were very helpful) If you do a stage2 jet from sea level to 3000ft. you need a 170main and 190 main needle, 31/2 turns out on your air/fuel screw. the pilot is adjustable with that screw... I hope that helps. It really should with the topend as your bike is built to endure some revs. For $40 or so, you can just get the dynojet kit, It comes with main jets of all sizes, a 190 needle, and instructions on how to install/tune your bike.

[CarGuy7a]

Originally posted by f150mann
sorry dont know much about jetting..something i hate to get into, so ill ask for a stock styled jet, 152 main and 40 pilot?

yeah i thought jetting was going to be a nightmare when i first started messing with it but after talking to knowledgeable people and learning what to look and listen for i can do jetting in a snap now.

actually if you're running pretty good with the stock pilot i would leave it in there. or if you want put the 40 in and try it.

that's pretty much how i learned was through trial and error. you'll know if you have your jetting off. it'll bogg if it's too rich or make a popping sound and cut out if it's too lean.

also i would recommend a Motion Pro fuel screw mixture tool. i bought one from www.motosport.com and it is well worth the money. no more twisting the carb or taking it off to adjust the fuel screw. although it does not work with 05 and later carbs b/c they put a goofy D screw it them.