carb question

[oldschool73]

Will an 05-06 carb off a 400ex fit an 03? There is a different part # for an 05-06 Than the one for a 1999-2004. what is the difference? thanks

[hornetgod13]

It will fit and work. The 05 and Newer carbs have a Non-Adjustable needle and a "D" shaped fuel screw. Other than that, the carbs are the same.

[oldschool73]

If I'm running bone stock will I ever have to mess with the needle? Why is it non adjustable? in your post I see you have an adjustable needle , is that what the dynojet kit is for ? The reason I ask is a new carb is 125.00 for the 05-06 but they want 264.00 for the 1999-2004. My carb is worn where the needle off the float slides up and down and it sometimes sticks causing gas to flow out the overflow tube.

[GPracer2500]

The non-adjustable needle and pain-to-deal-with "D" shaped fuel screw is to discourage you from messing with your jetting. Pretty much, you can thank the "greenie" alarmists for that.

If you stay stock (or even pretty much stock) the non-adjustable needle is ok unless you normally ride at 12,000ft or something. They can be shimmed to get them a little richer if needed for basic intake/exhaust mods. Or you can just buy an adjustable needle seperately from an 99-04 if it came to that.

I'd prefer the adjustable needle on principle alone--but it doesn't sound like you'll need it so don't worry about it.

[hornetgod13]

Yes, I have a DynoJet adjustable needle installed. The Jet kit came with it, 10 assorted jets, and a Fuel screw tool for the "D" shaped fuel screw.
If you stay close to stock than you'll be fine with the non adjustable needle.

[oldschool73]

Thanks for the info. this forum has helped me out alot.

[GPracer2500]

Originally posted by REDRIDDER
Hey guys im pretty sure that the carberator on the 400ex in 05-now started to use the 38mm Kehin or how ever you spell it.So if you have a 2003 youll actually be adding a couple of milli-meters over the stock 2003.

Same carb body. They just decided to measure it differently. Don't ask me why.

[oldschool73]

Well I just ordered a 2005-2006 carb for my 2003 400ex (hope it fits). For some reason a new 05-06 is 124.00 . They wanted 264.00 for a 1999-2004 if all it is , is the needle and fuel screw its not a problem as the machine is stock. I'll transfer my old needle set-up if i have to adjust it. If anyone has already done this swap please let me know if it is a direct bolt on (just for peace of mind) Thanks.

[oldschool73]

So I guess the question now is will the new carb fit my 2003 400ex or did I just throw 125.00 out the window? i got my fingers crossed? Would anyone in the know please let me know Thanks

[GPracer2500]

Originally posted by REDRIDDER
GPracer2500 i stand corrected by my self from 1999-2004 the 400ex carb is a 35.5mm in 05 they switch to the 38mm.I went and looked them up.I just hate being wrong but heres the correct info.

I realize that's what the specification releases from Honda say. What I'm saying is that I don't believe the size is actually different. There's more than one way to measure a carburator (apparently). If the carb's diameter actually changed then the stock jetting would most likely have been adjusted to suit. But it didn't. Also, certain parts of both the 99-04 and the 05-07 carb (such as the slide) that I'd think would be different if the carb bodies where different carry the same OEM part number. There are several parts that are different between the two carbs but none of them lead me to believe the venturi diameter changed.

My OEM honda service manual (1999-2002, so says the cover) lists the carb as 38mm. Page 1-5. Maybe the original press releases (saying 35.5) for the 400EX were wrong and it was never corrected until 2005? Who knows.

If someone can show me a picture that shows the two carbs side by side and one of them actually measures larger then the other then I'll stand corrected.

If I'm wrong about this then I want to know about it.

[GPracer2500]

Yeah, I know what the spec sheets say. I've looked into this before....see my last post for my thoughts.

[oldschool73]

I can't believe I am the first person to ever do this? Well the carb should be on its way when I get it I will take some side by side pictures. I myself find it hard to believe they are not the same carb, with just different jetting or emission controls. If anybody has done this swap already please let me know. Thanks

[oldschool73]

Here's the answer to the $64,000 question!
The 05-06 carb is a direct bolt on to the 99-04 400ex Other than the needle and D-shaped screw, The carb bodies are identical except for one small feature. The fuel nipple where the hose comes off the petcock to the carb. The fuel inlet nipple is a little bigger. The stock hose will stretch over it , but is definately alot more snug. I removed my tank when changing out the carb and the whole process took about 40 minutes.
I bought mine from Hidy honda in Ohio, they had a buy it now on ebay for 124.00 plus shipping I think the total was $132.00 . They wanted 264.00 for the 99-04 carb.
So if you have a stock machine with a worn out carb,you will be money and headaches ahead for just $132.00 with a brand new factory keihin honda carb.
My 400 started easier now than it ever had and runs like new.

[GPracer2500]

Good to know. I'm glad to have some confirmation on that. [thumps up]

[my88r]

buying my 05 tm. from service honda

[Got Boost]

buy a 450R carb from service honda, $165 and get some sweet gains, or I will sale youa 2001 carb.

[my88r]

Originally posted by Got Boost
buy a 450R carb from service honda, $165 and get some sweet gains, or I will sale youa 2001 carb.



pmed you

[oldschool73]

could the powers that be make this a sticky?or at least tell me how to link people to it , thanks.

[JOEX]

Originally posted by oldschool73
could the powers that be make this a sticky?or at least tell me how to link people to it , thanks.
Here's the link to this thread, save it somewhere and you can copy & paste it as needed :)

http://www.exriders.com/vbb/showthread.php?s=&threadid=287977

[oldschool73]

Thanks JOEX