# New Carb leaking



## Cubby (Dec 18, 2015)

I just installed a brand new Oregon 50-642 on my Tecumseh HMSK80. It is leaking gas from the main adjustment screw on the bottom of the bowl. The bowl is dry and its not leaking from the fuel hose (I closed the fuel shutoff valve).

Any thoughts (besides return it)?


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## Kiss4aFrog (Nov 3, 2013)

:welcome: to the forum Cubby


Have you tried removing the bowl and then checking if there's an O ring missing, cut, twisted ...


This is from a briggs:


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## Cubby (Dec 18, 2015)

I took it out and there is an o-ring and the gasket. I flipped the or ring over and re-installed. I will keep and eye on it.

Update - still leaking. I will get a new o ring for it.


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## sciphi (May 5, 2014)

Mine's having the same issue. I'll have to get a slightly smaller O-ring for the carb and try it.


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## bad69cat (Nov 30, 2015)

Try seeing if you can find a Viton O ring in the right size. They hold up much better.....


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## sciphi (May 5, 2014)

Another thing to consider is that the threads make a fairly poor sealing surface. Putting some epoxy or other gas-resistant stuff onto the lower-most threads where that O-ring rides to make a smooth surface might help it seal better. The original adjustment needle on my Tecumseh carb has a smooth area for the O-ring to seal on. The replacement has threads in that area. The replacement was impossible to seal, so back to the cleaned-up original main jet adjustment needle it was.


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## Toro-8-2-4 (Dec 28, 2013)

As sciphi said you may have better luck reusing the original needle. The o-ring needs a flat surface on the face and a smooth surface on the ID. If there are threads for it to seal against on on the ID you are asking too much from a conventional o-ring. I doubt a new o-ring will solve the problem. Make sure the bowl is relatively flat on the mating surface and there is not debris present. The spring needs to have ample tension too!

good luck.


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## sciphi (May 5, 2014)

Post #2 illustrates the issue I had nicely. The O-ring has to seal against the solid area on the adjusting needle. If it's not available, it can be made, or the original re-used after cleaning.


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## Cubby (Dec 18, 2015)

We haven't had snow in 3 weeks so I have been ignoring the snowblower. Its -27 C right now so I will wait for warmer weather to check the bowl and all mating surfaces.


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## kntrlme (1 mo ago)

I was using my troy bilt snow blower yesterday. It worked fine a little rich though. i **** it off moved to a new location and the off centered valve started leaking. The one with teh spring. NOT the center one. What can I do to stop it from leaking?


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## Oneacer (Jan 3, 2011)

That is not a valve, but only a drain for the bowl which is under spring tension with a tiny rubber or fiber seal. Usually removing the bowl, but remember its position, as the bowl only goes correctly on in one position. Take and work the spring up and down, while checking the tiny seal gasket condition and any flecks of debris. You might try lubing it with something, but most of the time that tiny gasket needs replacing. It is kind of neat that the drain is there, but I honestly rarely if ever use them, and just the slightest bump while adjusting the main adjustment will let it leak sometimes.


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