I have a Murray LT1000 riding lawnmower with 16.5hp Ohv Briggs & Stratton engine. I have a problem that just started a couple of weeks ago with the lawn mower sputtering, burping fuel out of the carborator,and then backfiring after running about 15 to 20 minutes. Then it is hard to start again and when it does it will only run in low and eventullay sputter, spit fuel, backfire,and shut off. But the next day it will start up fine and then run do the same thing again. A friend of mine told me it could be the fuel solinoid going bad under the bowel.He said it could be working fine when the engine is cold and when it gets hot the fuel solinoid starts to go bad. I have already cleaned the carborator and replaced the spark plug and that did not help. I am starting to think the fuel solinoid may be the problem does anyone have any suggestions or have ran into this problem?