05 crf100f bogs when you hit it hard

i have alot of experience cleaning carbs but this ones got me stumped everyone says the bog on these bikes is caused by jetting but i dont believe it more beliveable would be a common defect like maybe whats wrong with mine?????? yes this is a question and please explain to me if i am wrong   the passages to the jets seem to be messed up the offset one (connected to smaller jet) seems fine (compressed air travels freely) but the one feeding the large jet seems to be blocked a small amount of air passes but not freely SO i pulled out some wire and went diggin i can see where the wire stops by removing the jet but the wire will not pass through  ...              the fitting (pressed in carb casting) at the bottom of hole where jet screws in is blocking the port ...for the most part wich means i can bearly see a glimer of copper wire between casting and fitting ......????? shouldnt this prevent proper air flow causing bog or poor throttle response ....i believe the brass fitting im refering to is called the needle jet       ....??????????

how to remove needle jet?????    

Can you post a pic of what you are talking about.  The main jet is screwed on to the needle jet, and the needle jet is screwed in to the carb and the needle on the slide fits in to it.  It shouldn't be pressed in there, so we may be talking about something else.


The pressed in brass fitting is for the float needle.

sorrry no pics i am sure your right though fitting is deffinatly for needle and it blocks hole for passage through casting 98% i tried to clean this passage and noticed my wire would stick then noticed it was atempting to exit passage next to brass thing for needle but is in fact blocked by it

not float needle but needle on throtttle cable

my main jet is one piece the needle slide goes through the brass fitting were talking about and the fitting is deffinatly pressed in

This is typical of XR100 / CRF.  Rip the throttle open and the engine all but snuff's out - largely due to a lack of accelerator pump.


Many have tried, no one has found a way to tune it out without a serious sacrifice.

Edited by theraymondguy

This is typical of XR100 / CRF.  Rip the throttle open and the engine all but snuff's out - largely due to a lack of accelerator pump.


Many have tried, no one has found a way to tune it out without a serious sacrifice.

+1 on this. It's not only typical of xr100's, but most any carbed four stroke chokes when you yank open instead of roll on the throttle. An xr100 will never get you there faster than it wants to...........

4 strokes will die if you rip on the gas real fast, its just how they are and you can't fix it. If it does this more than normal then check your spark for strength.

It's a common problem that has to do with the bike only being 11hp at the crank (crank ratings are signifigantly higher than wheel ratings) I'm not sure what kind of mods people do to improve this, I sold mine before I got the chance to mod it.

To get the pressed in, brass holder out of the carb body is really quite simple providing the carb is completely disassembled.

With the slide completely removed, select a small screwdriver that the handle is plastic and will fit into the slide hole upside down.

I have only used a "Snap On" screw driver for this so I do not know if any other type will work.

Anyway, tap on the blade with a a small ball peen hammer until the top of the handle presses the needle holder down to the bottom of the slide bore.

Then with a small Phillips screwdriver tip, gently push the needle holder out the rest of the way. (It normally will Come out easy) and shouldn't have to be tapped out but that would be considering how gummed up it is of course.

Now do I really need to explain that the Phillips screwdriver tip needs to be larger than the needle that slides through the holder but smaller than the outer diameter of the holder otherwise you will damage the carb body the the holder presses into?

I don't know how anyone else does this chore, but I have never had a problem with this procedure in 43 years.

So select your tools wisely and disassemble away.

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