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Carburetor question

3669 Views 9 Replies 3 Participants Last post by  TC
Subject: The carburetor is on a B/S 20.5 HP Twin, Model 461777, type 0137E1 engine. Briggs code is 9710285A (1997). It has a 3 screw fuel pump. This engine has sit for years and the carb. was totally gummed up.
Problem: After cleaning the carb. and rebuilding the fuel pump, I can get the engine to run only with "full chocking" by hand. When I dump in fuel, the engine runs. So we know the carb. just isn't putting fuel to the engine. I have made sure that all the tiny holes are open.
So here is my question(s).
(1.) Does the carb. body gasket (part 273186) have to be soft and pliable? Mine is hard from all the years sitting.
(2.) Does the hole or tube up the bottom of the pilot jet (part 691431) connect with the two holes on the side of the jet? I can not get a small wire all the way up the center of the screw to the side holes.
(3.) And finally, what should I be doing next to get the carb. working?
Thanks everyone for you help and suggestions.
WTC
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No there is no fuel solenoid on this engine.
I don't know !

The symptoms you've described sure sound like a blocked passage way. If it were me, I would strip down the carburetor one more time and let it soak in 'dip' over night. Sorry, that's all I can think of....maybe someone else knows exactly what to do :)

Mark
IF YOU HAVE NOT DONE SO ALREADY. STANDING IN FRONT OF ENGINE. ON THE LOWER RIGHT SIDE OF CARB. THERE IS A PLUG PROBABLY 5/8". TAKE THE PLUG OUT. BEHIND IT YOU WILL FIND THE MAIN CARB JET. IT WILL SCREW OUT USING AN ALLEN WRENCH. TAKE OUT THE JET AND SCRUB THE HOLE IN THE CENTER OF THE JET WITH A WIRE. OR MAYBE A TORCH CLEANER WIRE IF YOU HAVE IT. MAKE SURE IT IS FULLY OPEN. CARB CLEANER AND COMPRESSED AIR WILL NOT CLEAN IT. IT HAS TO BE SCRUBBED. A COATING BUILDS UP IN THE HOLE AND IT WILL APPEAR OPEN BUT THE OPENING IS NOT LARGE ENOUGH FOR ENGINE TO RUN WITH OUT CHOKE BEING PARTIALLY ON. THAT'S USUALLY THE PROBLEM WITH THESE ENGINES. THE PARTS BREAKDOWN SHOWS A FUEL SOLENOID SCREWED INTO THE CARB INSTEAD OF THE PLUG FOR YOUR MODEL NUMBER. THAT'S WHY I ASKED ABOUT THE SOLENOID.

fifthstring27030
Fifthstring....
It is obvious that you know exactly what you are talking about so I'll start with a big "Thanks". I have soaked for 48 hours in carb. cleaner and wire cleared all the holes. Even the tiny one in the carb. throat ( where there are 3 very small holes). Anyway, the thing still does not get fuel so I am certain that we are back to the main carb. jet. Now the bad news is that the allen wrench will not take out the jet because it is stripped. I am sure that you are correct in saying that the hole is not cleared even if a wire can pass through. So do I risk messing up the carb. by using an easy out? Or is there a way to clean the hole with jet still in the carb? I used an easy out on a old carb. that I had on hand and the easy out worked great because of the soft brass. If it goes wrong as often an easy out does, I have screwed up the carb. for good. What would you do?
i would just run a wire through from the outside. I would not take a chance on ruining the carb
Hi Fifthstring....
Would you believe that I am now getting too much gas. Ha. I guess this means that I am making progress. Anyway, I have learned to take the carb. top off and on in less than 3 minutes. Maybe I can do NASCAR next year.
I do believe that I may at one point have had the main carb. gasket in upside down. While it fits just fine, it blocks the incoming fuel. The mower now starts and runs but I am getting too much gas. I can look down the carb. and see it pouring in while running and the spray comes out of the top of the open carb. It's like I put an oversize jet in the carb. No, I did not drill or change jets. So my questions tonight are .... is there a way to regulate how much fuel the carb gets and how do I adjust the float/needle to work properly? Thanks in advance for all your help.
TC
Ok to adjust float, hold carb top upside down with float attached make sure you hold it level. The float should be just short of parallel to the top by no more than 1/8" and it ok to be parallel but no more. There is no way to adjust fuel flow (sorry). if jet has been enlarged you will have to replace it and you'll have to try to use ez out to get it out. One thing bothers me seeing fuel squirt down thru carb is normal but seeing a spray above carb is not. That is a sign of intake valve not seating. Remove spark plug wires so engine will not start.Lay your hand on top of carb and spin engine. Your hand should be sucked to carb. If it blown off carb you might have valve problems too. It is possible for engine to run only on one cylinder so you may have problems on the other cylinder with the valves hence the blow back of gasoline
Hi Fifthstring...
I will follow your instructions for setting the float. It makes sense. I may have used the wrong work in describing the fuel spray out the top. I guess it is more of a "splatter" but anyway, the fuel comes up out of the carb. and we know that this is not good. I'll follow your suggestions. This has been a real learning experience. Thanks for your patience.
TC
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