Jetting question

[acw592]

Hey, I'm new to the site and just got a 400ex last week. I had a jetting question. Going to put a fmf megamax silencer on, and I've got a k&n filter. Not sure of elevation, live in Iowa and was wondering what main jet I needed. I was guessing 165 or 170. Also if it makes any difference, I'm removing the choke and installing a #42 pilot. By the way this is a great site!
THANKS!:D

[cals400ex]

i assume you leave your airbox lid on? if so, i would put in a 155 in the winter and a 152 in the summer. now, these are keihin jets, not dynojets. there is a difference. when jetting, bigger doesn't mean better most of the time.

[acw592]

I was going to buy the jets from the honda dealer. I'm not sure what brand they are.

[cals400ex]

where are you buying them from? i assume it isn't a jet kit is it?

[acw592]

No, I just called the dealer and was going to get whichever one I needed.

[nikejoe]

If you are just buying them individually at a honda dealer, you are probably getting kehin jets. I am running a 155 main k-jet and a 40 pilot with a white bros slip on. My needle is in the stock position. I am at about 800 - 1000 ft above sea level. This has worked well for me. Cal is definately correct bigger is not better!

[acw592]

I don't know where I got 170 for the main, but I will ask the dealer the brand and then try 152 or 155. Do you both think I should go with the 40 when I remove my choke?(instead of the 42)Thanks

[hondarider2006]

I went with a 42 piolet and it works awsome. 40 should work though;)

[nikejoe]

I think either a 40 or 42. I went to my dealer to get a 42 and my dealer said he would recomend a 40 for what I had. So that is what I got and it works great, but I have heard alot of people say that a 42 works fine for them. Take your pick!!!! Good Luck!:D

[acw592]

Thanks a lot guys for all the help!