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azdragoon

Seeping carb fuel inlet fix

8 posts in this topic

I've just finished cleaning my 426 carb after a year of sitting only to reinstall it and find fuel leaking out of the majority of packings due to drying out. The carb has a swivel fitting for the fuel inlet. I can't think of a single reason why on earth you would need a rotating fitting for your fuel line, unless your fuel tank is going to be constantly changing its position. Anyhow it has 3 o-rings on the rotating tube inside the carburetor. Yamaha doesn't sell these o-rings and the dealer told me I'd have to buy a new carb to get them because the microfiche doesn't show this as a replaceable part. I couldn't find any vitron seals of the correct size at several hardware stores and nitrol rings leak in fuel after a couple of days. I purchased a 90 degree fitting with 1/8 pipe thread and 1/4 barb on the other. The inlet in the carb is the perfect size to tap 1/8 NPT without re drilling. I wrapped several layers of Teflon tape to the threads and spun it in until it was snug and the fitting was facing toward the tank. No leaks and several hundred dollars saved. Just wanted to post this although I know most of you won't be interested, but maybe I can help a few of my fellow TT'ers out.

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I can't think of a single reason why on earth you would need a rotating fitting for your fuel line, unless your fuel tank is going to be constantly changing its position.
You mean like when you switch from your stock tank to your desert tank and back? Yeah, me either.

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So might this be, and a lot more workmanlike in the end.

http://www.allorings.com/

I'm going to look into it for the 250F. It's at the point where it needs to be kept wet to keep sealing. While I'm at it, I might check on one for the needle valve, too. I have no idea what I'll do with the extras except maybe give them away on TT (bags of 50 for $8).

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So might this be, and a lot more workmanlike in the end.

http://www.allorings.com/

I'm going to look into it for the 250F. It's at the point where it needs to be kept wet to keep sealing. While I'm at it, I might check on one for the needle valve, too. I have no idea what I'll do with the extras except maybe give them away on TT (bags of 50 for $8).

Were you ever able to get o-rings for the carb inlet fitting? From the measurements I was able to do, this looked like a unique o-ring size. Groove ID 7.3mm, width 1.4mm in a 9.3mm bore. Assuming a roughly 20% squeeze, I think an o-ring in the range of 1.2mm width should be right, but typical sizes are 1 or 1.5mm.

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Were you ever able to get o-rings for the carb inlet fitting? From the measurements I was able to do, this looked like a unique o-ring size. Groove ID 7.3mm, width 1.4mm in a 9.3mm bore. Assuming a roughly 20% squeeze, I think an o-ring in the range of 1.2mm width should be right, but typical sizes are 1 or 1.5mm.

Try these: (three are called for)

Yamaha PN: 3TJ-14564-40-00

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As a temp fix (if you need it) that lasts a bit more than "temp" I have successfully used Hylamar (sp?) sealant on them too, just dont get it IN the carb

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