Precision Small Engine Service

old motor to get running

Previous QuestionsCategory: Otherold motor to get running
Dave asked 7 months ago

Howdy Joe, I have a 12.5 hp briggs vertical shaft motor off an old turf power rider that I am trying to get running. the numbers off it are 289707 0154 01 9211054E. The problem with it is that after a couple of minutes running, the motor will vomit gas out of the air filter hole and die. I have replaced the float and float pin, the needle and the fuel elbow as it was shot. I also pulled the needle seat this morning and replaced that. I also pulled both screws on the exterior of the carb and blew cleaner through these and any holes on the screws I could find. I also pulled the main jet out and did the same with that. After all that, it is still presenting the problem. Any ideas?

1 Answers
Joe answered 7 months ago

It sounds like you covered most of the bases. However, I can only assume that you did the repair/replacement of parts correctly….and you know what happen when you assume something. Now, I have some questions. You say the engine is off a riding mower, is it being used on a rider or for some other application? Is it being operated in a level position? If you have another fuel source attached to it other than the factory tank and it is larger, it could have too much pressure for the inlet needle to control. You said that you took the carb apart and sprayed thru it. The carb should be completely disassembled and soaked to make sure everything is open. A plugged atmospheric vent will cause the carb to run over. When you are done with the carb it should be pressure checked to make sure the inlet needle and seat are working. I think if you check and do these things it should work correctly.