06 525 AC Pump

[philf63]

Hi i bought the Acc Pump from JD i have fitted the ac pump but it is leaking fuel only when you rev the engine

i put the old one back in and that one leaked as well

can anybody help to fix the fuel leak from the acc pump

[L-vie]

Do you mean its leaking around the gasket area of the AC pump assy.?

[Mike in Fresno]

lost an o-ring maybe, there are two small ones in there for the cover to seal against

[philf63]

mine has no Gasket just the acc pump and the o ring it only had 1 o ring when i removed

it

[Mike in Fresno]

there are two o-rings, one is recessed on one side and the other sits on the opposite side- as in one is on the carb body and one is on the AP cover.

[philf63]

thanks guys it was the missing O ring all good now

now hopefully when i take it out this weekend the 1/4 throttle bog has gone

[YamahaKris]

I'm missing the o rings . And mine slowly leaks . Where can I buy new ones ??

[Grandville]

I'm missing the o rings . And mine slowly leaks . Where can I buy new ones ??

My sons 400 is having the same problem. When we took it apart, we only say one. Replaced the one from the dealer and put back together. It still leaks, but less. I plan on going to the HW stare and try to find a set that has a similar size.

[highmarker]

smaller of the 2 orings on the ap pump cover has a flat on one side needs to oriented correct.

[Grandville]

The seal around accelerator pump continues to leak after a similar second o-ring washer was added. This bike is a 02 400EXC.

I have replaced the diaphragm. The small o-ring washer has been replaced. The parts came from a KTM dealer, but the diaphragm did not have

the metal base as the original. The small o-ring that came from the dealer was not flat on one side as Highmarker as observed. The one that

was in the AC pump, did have a flat side. I thought the flat side was the cause of the leak. Apparently, not. The carb diagram only shows

this Model carb with one o-ring rather than two as some of you have mentioned.

Any suggestion that would lead to stopping this leak would be most appreciated.

[highmarker]

    59031058000   U-RING ?

[Grandville]

59031058000   U-RING ?

Thanks. I looked on the diagram to find that part. I see it is described as an "U"-ring. That is one of the

parts that was replaced. The old part was shaped like an "O" and was flat on one side. It was

replaced with another "O"-ring shaped rubber washer. Seemed to match up. Don't know why they call a "O"

shaped ring a "U"-ring.

[highmarker]

just trying to help, check this out:   

 

 

http://www.motorcyclecarbs.com/_P13081.cfm

 

and scroll half way down here:   http://www.tokyomods.com/carburetion/carburetion.html