FIX !! Leaking carburetor on BRIGGS & Stratton Quantum 6.5HP

I had limited camera access, but I bought a Troybilt 6.5HP Lowes Self Propelled Mower for my neighbor. The previous owner stated fuel was leaking out of the primer bulb. After cleaning the carb 2 times I found out that Briggs and Stratton uses a rubber o ring for a needle seat instead of metal or brass like many carburetors. I used a small phillips head screw driver and wedge the head into the old o ring with a twisting motion and twisted the old o ring out. After buying the part # 398188 part or 49-036 Needle and Needle Seat Kit the mower runs like new.



17 thoughts on “FIX !! Leaking carburetor on BRIGGS & Stratton Quantum 6.5HP

  1. This video is awesome! I totally fixed my carb while simultaneously learning how a what a carb is, what is looks like, where it's located, and so on and so forth.

    I work with tools but my knowledge of engines is poor.  With this video I learned how to fix my carburetor on the first try! It was one of my greatest man achievements in recent memory!

    Thanks for the video!

  2. So… I had two mowers, both the kind in this video.  One was poor and the other very new.  The poor one runs, and the new one had the leaking gas coming from the carb. 

    When I took the newer one apart and got down to the washer you identified I realized I couldn't buy that part anywhere, so I ordered it on Ebay.  In the mean time I wanted to mow, so I took the carb off the old mower and put it on the newer one.  Eureka! It worked! I was pumped.

    This week the washer came in, so I installed it into the other carb and put that carb back on the older mower.  So.. Here is the Q…  When I fired it up it took several pumps of the primer button to get anything. Finally, I got some gas in it and it starts right up, goes for about 3 seconds and then chokes out.  I did it like 8 times before giving up. 

    Any suggestions?

  3. Your video was great . I felt like an expert after 5 min. took the bowl off my Quantum and it was so junked up I though I'd spray it off and see what happens . It ran like a new lawn mower  . THANKS !

  4. Gas was leaking from my air filter and the exhaust  (which is right opposite of the air filter. Would this be a carburetor leak or fuel tank leak? I am starting to think carburetor.

  5. An entire NEW carb is $20-25 bucks. Don't rebuild, replace. That old one has a ton of shaft and other parts wear. Also EVERY mower needs a fuel filter and a fuel shut off valve. Future issues solved.

  6. I have nearly the same model and a leak. I believe it is the gasket that goes around the JET screw as I inherited this mower and it didn't have one. I found something I thought would work but honestly lol.. don't think so, very slow drip. I'm hoping just swapping that gasket will fix it as I already cleaned and rebuilt the original carb.

  7. that hole is suppose to be there on that gasket….your new gasket will have one as well……but the gasket itself is torn and in need of a new one….also with ethanol formulated into most gas these days…it really does a number on these small carbs…eating the little rubber seats under the needle valve away…most times by the time this happens the mower has some age too it….so i just replace the carb…time is money in my business as a small engine tech….you can find these carbs on Amazon all day long for $15 bucks….i rather do that than change the needle and seat.and the thing still leaks fuel from carb wear

  8. I have the same leak issue….you said replace the needle also but didn't see you do it, is that necessary to fix? Also, do you just push the new seat down into that recess? I assume you retrieved the old red one from the same location? Thanks!

  9. I had one of these where I replaced the seat but the channel for the needle valve had corroded due to condensation. This restricted movement of the needle valve and it would sometimes not open. A new carb was $10. on ebay and now it runs like new. 799866 part number with choke.

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