Outdoor Power Equipment and Small Engines - Briggs spewing gas

Hi everyone,

I have a Briggs and Stratton 19hp.
Model 42E707
Type 2631 E1
Code 9902155A
Craftsman 917.270771

It is spewing gas from two small holes on the top of the carb and flooding out. I have removed carb and cleaned(was not real dirty) put back on, still did it. Installed carb rebuild kit, cleaned again and made sure float was working. Still have the same problem. Will crank fine and run for about 20 sec. and then dies from flooding. Anyone have any suggestions on what to try next. Thanks!

Sounds like the float is bad/sticking, or the needle is bad.

Thanks, but I've checked it twice, could not find any problems with the float or needle. I got a chance to look at it today, when I disconnect the vacuum line it stops spewing gas and seems to run fine but I know I don't need to run it much without it attached. Any help very much appreciated.

Thanks!

For gas to come out the top, the needle isn't seating. That's the only place fuel comes into the carb bowl. By unplugging the line, you are stopping the fuel pump...so naturally it runs better...at least until the fuel runs low in the carb. This one should have the plastic float...and I've noticed some that get distorted rub somewhere, causing it to stick open.

Thanks for the post. I replaced the float today and the needle was in the rebuild kit. Still spewing gas. The kit also included diaphram and gasket for the fuel pump. I did replace these also, but is there anything else I should look for in the pump?

Thanks

When you take the top off the carb, check for the float and needle valve to move freely. Also take the float and shake it by your ear listening for a sloshing sound, it is a brass float with a soldered seam that could be leaking. My guess is that the float is not moving freely on the pivot and is dragging on the side of the carb or the needle valve is also not moving freely. The pump only puts the fuel through the needle valve into the carb body. The float and needle valve must shut off the flow when the carb body is full. When you rebuild the carb, did you match up the gasket for the carb top to the old gasket for the correct holes arround the center of the gasket? There usually is two or more carb top gaskets in the kit. Also the kit usually has two types of needle valves, depending on which type of carb top is used and whether it has a fuel pump or gavity feed. Check your new parts to be the same style as your old. More than likely you will have a soft tipped needle valve. If the kit came with a new brass seat for the needle valve, was it replaced as if your old unit had a solid tip needle valve a grove could be worn into it and the new needle is not seating. Hope your not too confused as I have been doing this job for over 50+ years and have my hands full of new techs taking short cuts and trying to figure out what and try to train them correctly.

Ok i also have a 19hp twin cylinder briggs. i found your post because i was trying to figure out why mine was doing the same thing... if you are still having trouble try this.. i also tryed rebuilding the carb several times. tryed replacing the fuel, the fuel filter.. until i checked spark.. i did have spark but it is weaker that i thought it should be... i replaced the coil pack and wow , not it starts right up and runs with out flooding out .. i think the spark was just enough to get it started but as it ran for about 20 seconds it would load up with fuel that the week spark couldnt ignite.. let me know if you found the same to be true...thanks Tony