Rebuilt my Walbro carb, but it still leaks gas

Archie06930

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Bought a rebuild kit and did a thorough job cleaning the carb up, put it back together and got my engine going again, but it leaks fuel as if the inlet jet is bad. This is an LMT Walbro, Briggs part 793224 on an 18 hp Craftsman I/C engine. Tried a new float needle, figuring there might have been a problem with the new rubber tipped one in the kit, but it made no difference. Since the float is nonadjustable, that leaves the brass needle seat which I didn't replace since it looked fine to me and would be a pain to get out. Anyone have similar problems after a rebuild?
 

reynoldston

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Looks like the needle seat is just pressed in, never did that model but it looks like you could just pull it out with a easy-out and press the new one in? Why can't you adjust the float maybe made of plastic and if so is that all right? For light duty pressing like this I use my drill press (not running)
 

ILENGINE

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I use one of the bolts out of my small briggs flywheel pulley slid through a 1/4 inch drive 10 mm socket. I screw the self tapping bolt into the seat and then turn the pull nut to pull the seat up into the socket, then use the old seat to press the new seat back into place and then blow compressed air into the new seat to remove any debris. You can also sometimes use a littler valve grinding compound on the end of a q-tip to polish the seat to get it to seal (doesn't work all the time but most of the time), then make sure to get all of the compound washed out.
 

reddragon

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when does it leak...stopped or running?.....does it mess up the running?.....does it leak back out past the choke?
 

Archie06930

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That's my next task then, pulling the carb and removing/replacing the brass float needle seat. I suppose it could be nicked or something I can't readily see (although I can't understand how it could get nicked with a rubber tipped needle valve) anything wrong with it, and I did a pretty good job of cleaning everything with a wire then compressed air. Many thanks to everyone for your suggestions; hopefully I can get it back on track so it doesn't leak gas when the engine is off and it's parked.
 

Archie06930

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That's my next task then, pulling the carb and removing/replacing the brass float needle seat. I suppose it could be nicked or something I can't readily see (although I can't understand how it could get nicked with a rubber tipped needle valve) anything wrong with it, and I did a pretty good job of cleaning everything with a wire then compressed air. Many thanks to everyone for your suggestions; hopefully I can get it back on track so it doesn't leak gas when the engine is off and it's parked.

Well, I pulled the carb this morning and took out the float and inlet needle to get to the brass jet insert. I noticed the needle no longer has a rubber tip. Are these needles all metal with a rubber coating over the tip? I thought they were different than the all steel needles, and that the rubber tip was separate from the body of the needle. Is it possible our gasoline has so much ethanol in it that it dissolves the rubber over the course of half a week (Tuesday, when I bought a new needle and replaced it). I used Briggs and Stratton part number 231855S which is the rubber-tipped needle. Anyone ever hear of this happening or had any experience with it happening?
 

reddragon

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i think you found your problem....never seen any thing like that
 

reynoldston

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Well, I pulled the carb this morning and took out the float and inlet needle to get to the brass jet insert. I noticed the needle no longer has a rubber tip. Are these needles all metal with a rubber coating over the tip? I thought they were different than the all steel needles, and that the rubber tip was separate from the body of the needle. Is it possible our gasoline has so much ethanol in it that it dissolves the rubber over the course of half a week (Tuesday, when I bought a new needle and replaced it). I used Briggs and Stratton part number 231855S which is the rubber-tipped needle. Anyone ever hear of this happening or had any experience with it happening?

It looks like a defective part to me never heard or seen that happen even with ethanol in the gas.
 
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