O-Ring for the airscrew?

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Bailey28
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O-Ring for the airscrew?

Post by Bailey28 »

Since dialing in the RB carb mods, the bike has been running great!

After putting more miles on the bike, I have noticed that a slight amount of fuel is leaking from the airscrew threads on the outside of the carb. It is not enough to make a drip or see it when it is running, but enough to cause a sloppy mess of dust, dirt, and oil residue. Float bowl gasket is good, the mess is coming from in between the brass a/s and the carb body a/s threads.

In Eric Gorr's book, he shows a Keihin carb with an o-ring as part of the assembly. I checked buyKawasaki and only found the screw 16041 and the spring 92081 listed in the assembly.

Has anyone else had this minor issue and found a small o-ring to keep the fuel in and any excess air out?

I have also thought about taking the screw out and applying RTV red to the threads of it then assembling it when dry. Any ideas?
FAZ
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RBD
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Post by RBD »

Wash your bike after you ride!

It is an air mixture screw......., any fuel leakage (is almost normal) might be from leaky or bad reeds spitting back into the air bleed and air correction circuits.

Most o-ring sealed mixture screws are 4 stroke carbs. They are fuel mixture screw (your carb is not of this type) The PWK is an air mixture type (this is your carb).

I did try to incorporate a o-ring into my mixture screw, but the carb body and the mixture screw limits did not allow this.

So you need to clean your bike a little more often or look for a spit back problem.

Ron
Bailey28
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Post by Bailey28 »

Thanks Ron, believe it or not, the bike gets washed after every ride. The build up comes from one ride! :shock:

I put in new Boyesen 607's after I got the carb back from you, the reeds may have 15 hours total on them. With the PC Platinum II, the bike has great low end and I never imagined that a spit back problem was occurring. I have always had the "pool" of purple 2R sitting in the bell mouth of the carb whenever I look, as mixture oil seems to hang out there, and in the reed housing on the bottom left corner.

32:1 with pump gas... Plug looks good.... It's not a major issue, but I noticed the leak more with the 607's than with the stock reeds. Air filter is cleaned and oiled regularly, with the PJ1 red spray oil.
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Post by KDXer »

I used to get it also on my stock carb with a VF2 reedcage. Haven't noticed it on the RB'd Airstriker, yet...
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canyncarvr
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Post by canyncarvr »

Do 607s have an 'up' and a 'down'?

Most reeds do. Comes from them being cut.

The smooth side fits to the cage, the rough side don't.

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Post by Bailey28 »

CC,

Thanks, I'll pull them out and take a look at the rough vs. smooth. When I assembled them I recall flipping one side, as in the resting position one reed was lifted about .010" off the surface of the block.
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canyncarvr
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Post by canyncarvr »

This opens up a whole 'nother can of worms.

One would assume the reeds should be seated with some tension against the cage. A reed that is NOT seated that way is obviously sprung, bent OR the reed cage has a problem, right?

That is not what I have been told. I went through multiple reed&stop configurations with MotoTassinari for the DF2 reed system. I asked them that exact question when I found one of their setups did NOT seat against the cage. They told me it was fine...that the reed would seal when backpressure from downward piston movment was exerted on the reed block.

That never did sit very well with me, but this is in fact what they said.

As noted earlier, reeds will have a rough edge left over from the stamping process that formed them from the stock material sheet. Carbon reeds seem to have a sharper edge than fiberglass..that I presume being due to the qualities of the stock material.

I recently replaced the reeds in my VForce3. I noted that in the existing configuration every petal was installed with the 'rough' edge OFF the cage. I put the new reeds in the same way.

I have generally installed reeds in that way. This last time I just happened to pay particular attention to the orientation of the existing reeds.

There are other reasons for reeds to not seat on the cage..a deformed or damaged cage for one. Some foreign junk in the way is another.

If the choice is rough out..reeds not seated or rough IN reeds SEATED, I'd choose the latter.

Reed cages do wear. Consider how many times the cage gets slammed with the reed edge during a days ride! If you see any depressions on the cage where the reeds seat or if any material is missing from the cage..it's no good.

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