QuestionI’m stuck. I have a Craftsman 18.5 HP lawn tractor, Model 917.273643, Engine B&S 31P777-0348-E1. It will fire and run as long as I feed it fuel (with starting fluid or gasoline poured into the fuel line (after the fuel pump, before the carburetor). Runs fine, then dies after the fuel is gone. I think I have done pretty much everything. I removed and cleaned the gas tank, replaced the fuel line from the tank, replaced the fuel filter (a couple of times)- fuel runs freely to the pump, replaced the fuel pump (a few times), replaced the vacuum hose and clamps, and cleaned and reseated the oil dipstick housing (to which the vacuum hose is attached). I also removed, disassembled and cleaned the carburetor and removed and bypassed the fuel shut off solenoid. More recently, I bypassed the fuel pump and the thing runs with gravity feed –however, after 5 or 10 minutes, the rpms rise and fall for a few minutes and it shuts off. I put solenoid back on; no difference. At one point while running on gravity feed, I had the vacuum hose still hooked to the fuel pump (which was not hooked to the carburetor). I noticed oil coming out of pump, which was also in the vacuum line. Oil level is on low side, but OK. I cleaned the vacuum line and it runs as described above (gravity). I want it to run properly and with the pump attached. What am I missing??
Thanks, Janis
AnswerTell you what, I just have to say with what I read, this problem is in the carb, and or the fuel pump. Only other thing could be a blocked air vent on the fuel cap. You said you replaced the fuel pump, or rebuilt it? Said you cleaned the carb, did you check each, and every fuel circuit with a tiny wire? Did you rebuild the carb, with a kit, or just clean it? If it has a fuel pump it must be the Nikki carb, the Walbro is gravity feed. The one you have is like a Honda carb. Something is being over looked....Tom
