Mower not idoling as it should.?
I have a craftsman LTX 1000 21.5HP vtwin Briggs and Stratton motor 42" . We changed the spark plugs and put new gas in it the mower and changed the oil before using the mower. I mowed the grass saturday and once I was about 80% done the lawn mower began to sputter and blow black smoke and had no speed. We added more gas the oil was fine, etc and than we changed the fuel filter and the air filter. It still would not run properly. After we worked on it for awhile we have found that if you pinch the fuel line coming from the fuel pump it will idol as it should but once you let go it goes back to the way it was idling low etc.
Please help
Sounds like the float valve is not closing. I would try some fuel system cleaner in it. If that doesn't help you may end up removing and cleaning the carburetor.
