Carb way too rich

[Piet]

My bike is running way too rich. It splutters, smokes and don't want to get away.

I have tracked the problem to the jet needle or main jet passage.
How do I fix this?
Can the part be replaced?
Can I buy a center portion (only 2 screws hold it down)

[Julien D]

The most common cause is the gasket underneath that jet block. It's a rubber o-ring type gasket, and if the carb was ever soaked, or dipped, it is likely deteriorated and leaking. I know SUDCO had those gaskets available.

[Julien D]

http://www.jetsrus.com/individual_parts/021_532_su.html

I believe that's the one.

[bufftester]

The most common cause is the gasket underneath that jet block. It's a rubber o-ring type gasket, and if the carb was ever soaked, or dipped, it is likely deteriorated and leaking. I know SUDCO had those gaskets available.

+1 It gets overlooked usually during carb rebuilds, but when it goes bad you'll never get the jetting right. Not hard to replace (hardest part is getting a stupid security torx bit)

[Piet]

http://www.jetsrus.com/individual_parts/021_532_su.html

I believe that's the one.

Thanks for that link. Was looking where to buy these parts. I see they sell everything.

Pitty: $4 part $20 shipping.

[Julien D]

Yeah. Throw in some jets and anything else you might need. You can also check psep.biz and sudco.com to see if they have it and check if you can get a better shipped price.

Sent from my HTC6500LVW using Tapatalk

[Piet]

The most common cause is the gasket underneath that jet block. It's a rubber o-ring type gasket, and if the carb was ever soaked, or dipped, it is likely deteriorated and leaking. I know SUDCO had those gaskets available.

+1 It gets overlooked usually during carb rebuilds, but when it goes bad you'll never get the jetting right. Not hard to replace (hardest part is getting a stupid security torx bit)

Yes the seal is buggered which I noticed when cleaning the passageways but I got it sealed temporary for testing.

I am fairly sure that the problem is with the needle passage which is too big. Measured one against the other and you can even see it in the photo below.

The part looks replaceable, but can't find any info. The other option is to go bigger with the needle diameter but keep the taper?

Pic below are both from PWK35 Carbs. The one on the right is on my KDX 220 but not sure from which bike it came originally (converted from 33 to 35)

[Julien D]

I'm sure I wouldn't trust that not to leak, even with some sort of sealant on it. It does look like that has been bored, which I know some tuning manuals called for. It does seem that the larger bore in the needle jet would call for a much larger jet needle. I have never seen anyplace sell that jet block separately.

*At another look, that jet block has a few other obvious differences as well. I'm not familiar enough with OEM PWK vs KDX PWK differences to tell if that's what's going on here, but it very well could be. You're sure it's a PWK 35, yes?

[Piet]

Yip, don't trust the seal either in the long run, but it will be a while before I get a proper seal, meanwhile I have to make work with what I got.

If I can get the jet block to work I suppose a new carb is the only option.

The differences I noticed is the idle / pilot hole which is smaller and the the little slot in the alloy plate around the needle jet.

Pretty sure it is a PWK35. Looks identical to the KDX200 carb and the measurements on the outlet side is as per web info.

[Tedh98]

Pitty: $4 part $20 shipping.

I take it you aren't in the US?

I just ordered a couple jet block gaskets and a few other items. Shipping was $7. They sent it out same day.

[Piet]

Pitty: $4 part $20 shipping.

I take it you aren't in the US?

I just ordered a couple jet block gaskets and a few other items. Shipping was $7. They sent it out same day.

Yip, in South Africa.
Shipping is not a problem if I can buy everything in one go. Just have to make sure of what I need.
But now there is no point in buying a gasket if the whole jet block is wrong/stuffed.

Anyone out there with an old or damaged carb that want to sell me a jet block or even a whole carb?

[Tedh98]

I've got an extra carb, but one of the gaskets I bought will be used to fix it up so I can sell it.

[Piet]

What sort of price are you looking at?

[Tedh98]

Not sure yet, I want to get it running correctly first. I put the carb on and rode around the yard. It ran pretty well considering the float bowl gasket was leaking and gas was dripping down the sides. I ordered that gasket and the jet block as well, figured it wouldn't hurt to replace it as well.