Unidentified jet... anyone can help??

[forestbrian88]

1718103224i was posting in the 400 ex jetting help (the one with the poll)
and i havent got any respond concerning this..
just so i can reassemble my carb before i get my jets... id like to know if this is going there?
i dont see it on my manual and it was there before and the bike was running

Here is what is on the picture

A Main Jet (142)
B Is my current question
C Is my Pilot jet (38)
D is my Needle jet Holder

Any help would be appreciated thanks!!

[Zakradu398]

1718103224i was posting in the 400 ex jetting help (the one with the poll)
and i havent got any respond concerning this..
just so i can reassemble my carb before i get my jets... id like to know if this is going there?
i dont see it on my manual and it was there before and the bike was running

Here is what is on the picture

A Main Jet (142)
B Is my current question
C Is my Pilot jet (38)
D is my Needle jet Holder

Any help would be appreciated thanks!!


What do you need to know?

[forestbrian88]

If i need this part or not?
the Main jet was screwed inside this (ill call adapter)
but i dont see in any schematic of this carb that little adapter...
so im a but confused as of puting it back or not?
its the one Labeled B on the picture

edit: u was looking at picture in my manual and i think its and adapter to make the jet sit lower in the bowl...
si i guess this means it as to be at the lowest point inside the bowl? would removing it lean me more or richen me? im at sea level and by judging from the manual... im runing for High altitude Lean honda seting + im lower altitude and higher flow? something is not right should of burn my engine with all the beating i gave it lol

[CJM]

A and B are dynojet adapters. You dont need them at all. Replace with a keihin hex jet.

[forestbrian88]

now i understand a bit better... so they changed the main jet for a smaller without noticing i guess...
so this means my 142 dynojet is around 155 keihin value?

[JOHNDOE83]

on the jets rus website theres a jet size converter for minkuni, dynojet and keihin.

[forestbrian88]

Thanks for the info at least i know its where it was supose to be... because the jet could screw in where the keihin would so i was confused as of how to install it... would of it did a differenec if i would of not put the adapter? i know i changes the location of the jet inside the bowl but as far as Richness or lean... would of it change anything?

[CJM]

Its just an adapter to run a different type of jet. Me, I personally hate them as they are manufactured crappy and are imprecise overall.

Just junk part B and try a 150-155 main.

[forestbrian88]

Its just an adapter to run a different type of jet. Me, I personally hate them as they are manufactured crappy and are imprecise overall.

Just junk part B and try a 150-155 main.
well ive put everything back as it was... i could trow away the adapter but it would move my jet higher in the bowl, my only concern here is will it still run ok? (ill probably end up trying it...)
and ive looked on jets R us and it seems that my 142 Dynojet as u said it was... is a value of 155 keihin so ill be trying to mess with my carb tomorrow if the rain stops and when i get my Wideband O2 next week ill do a follow up of how im running with my carb

[CJM]

Bottom line is you need to run that adapter if you use the dyno jet, you run the keihin jet you dont.

[2001400exrida]

if you already have dynojets, you will want to keep that adapter in place. just keep it screwed in and remove your main jets from it. When CJM said you don't need the adapters at all, he was basing that on the fact that you don't run dynojets at all and switch to the keihen brand. If you want to run dynojets you will need that adapter, end of story. I don't run dynojets anymore, but i do have my 2007 400ex tuned with dynojets and it runs tip top. Many people use the dynojets, but if you're doing alot of tuning and adjusting with motor mods it's just easier to run the stock jets.

[forestbrian88]

ok so friday i should be receiving my Jets
ordered 40 and 42 pilot
150, 155 and 158 Main
Hotcam Stage 2 gets in Saturday along with my yfz450 Front Calipers :)
Today i just finished my Front end A-arm bushing where Shot badly... ended up finding a broken Lower A-arm... will post some Pictures if anyone wants to see :p