Jetting help

[Yurshia]

My brother has a 2007 400ex with full hmf sport exhaust, 6degree timing key, stage 2 hotcam, 13tooth front sproket and 39tooth rear, currently running 93octain untill we can find better, k&N air filter and EHS racing power lid.
we ride at about 1100ft elevation. If any1 could put me in the ball park of what jet sizes to start at i would be very great full.

[honda400ex2003]

164 would be my guess to start. it may be a bit rich with that but you shouldnt be too bad. steve

[Chipotle]

03 400ex, stock Carb stock jets, Yoshimura, AMSOIL Ea Universal Dry flow filter with Amsoil pre-filter, ehs racing lid.
14t front sprockt.
I run all 93 fuel.
I know its probably running way too lean.
My header is dark blue within 4min of warm up.
I ordered a 42 pilot and a 152 main.
I plan on removing the choke.
Currently I am getting popping in the Carb and backfiring.
I live in FL so my elevation is 1-30' at the most.
Any advice would be great.

[Yurshia]

Originally posted by honda400ex2003
164 would be my guess to start. it may be a bit rich with that but you shouldnt be too bad. steve

Thanks

[Chipotle]

bump... i could really use the advise

[honda400ex2003]

i would say that around a 158 would be a good starting point with no lid. needle on the 3rd clip position to start off, put the 42 pilot in and go abour 2.5 turns out on the f/a screw. you may be a bit rich with that but it is hard to say. steve

[Chipotle]

Thanks!
I ordered a 152 that will be in Wednesday.
If I use it what settings should I try with it?
I will order a 158 but wont be here in time for this weekends ride so I got to work with what I have.

Also where is this screw that I adjust?

[honda400ex2003]

it may be ok with the 152 i am not sure, i doubt it will be good though, sounds too lean with the lid off. If you are lean you can put your lid on for the weekend to make up for the lean condition until you get a bigger set of jets. I would suggest getting a few jets since it could be different from what i recommend. there are many factors to consider that i cannot do when suggesting something. Elevation, temps, flow, lots of things to consider, i try to always go to the rich side of any recommendation so that it is not at risk of blowing up. The f/a screw is on the bottom of the carb in front of the bowl. I would definitely do some researching and such to learn about jetting before doing it. it is not as easy as just changing jets it is really a science and can take lots of time to figure out if not done right. you will probably want to do some plug chops, do a search for this and see how to do it, along the way read the threads along with the plug chops and it will get you a better understanding of the whole thing. There are certain parts that are important during different times in the throttle position, such as a pilot being from idle to 1/8 throttle, needle from 1/8 to around 1/2-3/4 and main from 3/5 to full throttle. this is an estimate since i did not look to figure out what it is exactly. steve

[Chipotle]

Thanks Steve!
I have rebuilt Boat carbs in the past but these are a bit different.

I will run lid on this weekend. As of right now I think I am over heating within just a few min of riding.
Within 4 minutes of idling my exhaust is a dark blue.
I am scared its way to hot.
I cant keep it idling with stock jets and lid on without giving it 1/8 - 1/4 throttle.
I have been smelling a weird smell wile running recently. (dont know how to describe it.)

[honda400ex2003]

i would say you should be really close if not a bit rich with the lid on with your slip on and the filter. I ran a 150 with my t-4 and k&n at 1500ft. if you are at sea level a 152 will be just about perfect for you. I would suggest leaving the stock pilot in and going 3 turns out on the f/a for the weekend. this way you will not be changing too much and making it run worse than it already is. just my .02 though. lol. steve