jetting and air/fuel screw ?'s

[400exjoker]

ok so i got an 04 400ex and i took the plug out and it looked lean, all that is done to it as of before taking the plug out is a uni air filter and no spark arrestor with stock jetting..

well i just ordered an hmf slip on a plug tool, and all the main jets from 152-165 and a 42 pilot well i got the jets and plug tool in the mail already (pipe should be here monday) ive been riding the quad and always noticed i had a slight crackle on decel

today i decided to check the plug now that i have the tool, its showing lean... i didnt want to take the carb off today so i didnt put the 42 pilot in but i put the 152 main in it and took the lid off to see how it ran going down the road, well it did run better than it did with the 148 in it i put the lid back on it and ran it down the road and it still had the slight crackle in it so i "attempted" to adjust the air/fuel screw i probly got it turned about 1/8 of a turn out and it almost eliminated the crackle but its still there....


so heres my questions(lol) how in the H-E double hockey sticks do you adjust the air/fuel screw without buying more tools... and do you think that 152 main and 38 pilot is good for lid removed/modified and modified baffle for riding this weekend i get my hmf slip-on in on monday when i plan on putting the 42 pilot in and rejetting...

[chevymanrick]

U have 2 options for the air/fuel screw, but the d shape bit off amazon for like 2 dollars or buy a rebuild kit for your carb, it'll come with a normal flat head type screw. Your jets will be okay for the weekend, but the 152 is still lean esp. With the lid off u should Probly be around a 158 or so with your exhaust, put the 42 in and it'll be a lot better.
I have heard a .22 shell bent to fit works good for adjusting the air/fuel screw.

[CJM]

04 has the normal screw, 05 has the d shaped one.

I just loosen the carb and twist it so I can get a small flathead in there. Supposed to adjust it while running, but I found if you put it about 2.5-2.75 turns out from fully in it should be fine.

[chevymanrick]

Originally posted by CJM
04 has the normal screw, 05 has the d shaped one.

I just loosen the carb and twist it so I can get a small flathead in there. Supposed to adjust it while running, but I found if you put it about 2.5-2.75 turns out from fully in it should be fine.

I don't know how people adjust it when its running, its dam near impossible to get anything in the to adjust it on mine unless you twist it like u suggested

[400exjoker]

Originally posted by chevymanrick
I don't know how people adjust it when its running, its dam near impossible to get anything in the to adjust it on mine unless you twist it like u suggested

yea thats my problem even with a screwdriver with an 90 on it i can barley get to it and when i turn it i can get it turned any more than 1/8 of a turn cuz of location its in

im going to be running lid on unmodifed till i get my pipe


thanks CJM ill try that and see what happens

[Reece616]

I just got this http://www.rockymountainatvmc.com/p/43/53/213/1151/-/13581/Tusk-Fuel-Mixture-Screw/FUEL+AIR+MIXTURE+SCREW

and installed it today.
It went in fine, and when I turned it out about 2-2.5 turns the bike started up and idled great.
I'm gonna try tomorrow again after it's been sitting all night and see how it is.
Also, I'm gonna take it for a ride tomorrow as well and make sure everything's good.

For $12 it's a good deal and could help you out.

[TheAwesomehonda]

http://www.motosport.com/dirtbike/MOTION-PRO-90-DEGREE-CARB-TOOL-WITH-BITS That is the tool you need if you want to adjust your a/f screw while its running without moving the carb. I have one and it works.

[400exjoker]

Originally posted by TheAwesomehonda
http://www.motosport.com/dirtbike/MOTION-PRO-90-DEGREE-CARB-TOOL-WITH-BITS That is the tool you need if you want to adjust your a/f screw while its running without moving the carb. I have one and it works.

yeah that tool may work for you but it dont work good enough for me to pay $66.99, if im paying that much for a screwdriver to some one they better give me a reacharound or something



Originally posted by Reece616
I just got this http://www.rockymountainatvmc.com/p/43/53/213/1151/-/13581/Tusk-Fuel-Mixture-Screw/FUEL+AIR+MIXTURE+SCREW

and installed it today.
It went in fine, and when I turned it out about 2-2.5 turns the bike started up and idled great.
I'm gonna try tomorrow again after it's been sitting all night and see how it is.
Also, I'm gonna take it for a ride tomorrow as well and make sure everything's good.

For $12 it's a good deal and could help you out.


thats a bit more my style it works with the stock carb right?

[Reece616]

Yup, that's what I have.
I think it asks for a model and the 400ex isn't listed so I entered 2009 crf250x.
I'll report back tomorrow on my findings again.

[TheAwesomehonda]

Originally posted by 400exjoker
yeah that tool may work for you but it dont work good enough for me to pay $66.99, if im paying that much for a screwdriver to some one they better give me a reacharound or something





thats a bit more my style it works with the stock carb right? haha i'm not to woried about the price..

[400exjoker]

Originally posted by TheAwesomehonda
haha i'm not to woried about the price..

must be nice to have more money than brains (no offense)

[CJM]

Reece, what model did you buy the screw for? It doesnt list any hondas

[400exjoker]

Originally posted by CJM
Reece, what model did you buy the screw for? It doesnt list any hondas


im obviously not Reece but if u look at the part numbers they are all the same so i don't think it will matter, that being said... i haven't tryed any of them so my knowledge is all speculation

[Reece616]

I ordered it for the 2009 crf250x.

[CJM]

Thanks guys.

[Reece616]

No problem :)