2000 400ex slip on jetting

[05trx300ex]

I have a 2000 400ex and I just bought a lrd pro 4 series slip on exhaust and k&n air filter, everything else is stock.

I looked up the recommended jetting on the lrd website it says: 165 main jet, clip position 4th from the top, 50 pilot jet, and mix screw 2 turns from closed.

Does this sound right? Does a 50 pilot seem to big? Let me know what you guys think, i haven't even installed it yet.

[honda400ex2003]

yup, i would not go any bigger than a 42 ever. I would stick with the 38 unless you live where it is cold all the time and need it to start at 30 below for a long time. I would go to about 3 turns out on the f/a and see how it is there with the 38. or a bit less with a 40. also a 165 seems a bit rich too but it may be alright where you are at if you are close to sea level. Just my .02 though, steve

[05trx300ex]

I live in Michigan but don't plan on riding in cold weather. I am at 850 feet above sea level.

I would also like to keep the air box lid on but the lrd website didn't specify.

[honda400ex2003]

that jetting may be with a lid off considering i am at a 170 with a 416 and my lid off. I ran a dynojet 138 when i had my just my t-4 and and k&n. I am not sure what the conversion is but i am on the other side the lake and am about 1000 with the 138, 3 position down on the clip and 3 or 3.5 turns out on the f/a. good luck with it. steve

[05trx300ex]

I looked it up and a 138 dynojet is equivalent to a 150 Kehein main jet.

[05trx300ex]

I'm not sure what to go with now, I know I need a bigger pilot because it's cold blooded.

[honda400ex2003]

alright that is what i was at then. you can put a 40 in it and just mess with the f/a to get it where you want it. It was pretty good for me. you could be a bit over that being a bit lower elavation. or if your exhaust flows a bit more than mine does. I would go with about a 155 keihin to start with and go down if needed. i would think you should be rich enough with that. You could even try the jetting recommended to see how it runs, I think it will be quite rich though. Good luck, steve

[honda400ex2003]

Oh and do a plug chop after any changes to see where it is at. just make sure you have a bunch of plugs if you want to get it perfect. Steve

[BEAVER.989]

152 to 155 on the main and 40 to 42 on the pilot. Drop the needle one clip.

[Snipe]

If it was just a slipon with stock air flow I would say 1 maybe 2 jet sizes over stock. With K & N I agree a 155 would be a good starting point.

Im running a UNI and a White brothers full exhaust and im running stock idol jet and a 172 main.

[05trx300ex]

I went with a 155 main, 42 pilot, and stock needle position and it runs great, thanks everyone.