6.75 HP B&S engine leaking fuel from air filter

[tbweng]

After rehauling a carb (kit part no. 498260) from a 6.75 HP B&S mower engine (125k02-0243-E1), fuel is leaking out of one of ports by the air filter. I believe the carb is flooding and preventing the engine from starting.

Naturally, I thought the problem was with the needle/needle seat or float. But, I'm confident that the new needle and needle seat are installed correctly, and the float has no cracks and moves freely. I was sure to insert the rubber seat with the ring cut faced downward (opposite from where needle contacts the seat), and I used a 3/16 drill bit to set the seat firmly. The float appears to be level (it's parallel with the carb). I've cleaned all ports thoroughly with a wire and blown compressed air through them.

After taking apart the carb several times, I'm running out of things to try. Any other troubleshooting suggestions?

 

[ILENGINE]

Most likely the new needle and seat isn't sealing. It wouldn't be the first one I have had that didn't work , and had to install a different seat because it wouldn't seal, with the parts that came in the kit.

 

[tbweng]

Most likely the new needle and seat isn't sealing. It wouldn't be the first one I have had that didn't work , and had to install a different seat because it wouldn't seal, with the parts that came in the kit.

I tried buying another needle and seat kit and it was still seeping fuel into the air filter housing. Someone else suggested that I might be driving the seat too far down into the inlet. I'm going to try backing it out a bit to make a tighter contact with the needle.

 

[Rivets]

Are you sure you installed the seat correctly. One side of the seat has rings on it, which must be installed against the carb body. The smooth side of the seat contacts the needle. Another cause for leakage after rebuilding is that the gasket between the carb body and float bowl is not seating properly, not sealing the bowl cavity properly.

 

[bertsmobile1]

Test it by working the float up & down without the float bowl in place.
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