The old Simplicity tractor ran out of gas as I was spraying my fruit trees - filled up the gas tank and started it but it wouldn't run right - it would speed up and down and then it finally stopped - figured that some dirt got into the carburetor when the gas tank got empty - I changed the fuel filter, fuel pump, air cleaner and then bought an after market carburetor instead of rebuilding or cleaning the old one - put everything together and tried starting it - no go - checked for spark - got spark - checked for fuel - got fuel - now what - well I took off the new carburetor and put on the old one after taking it apart and cleaning it - tried starting it - bango - she started and ran beautiful - moral of the story - don't buy the Chinese made junk they sell you - sure it costs a lot less but you never know what your getting - that goes with car parts too - a lot of people put the junk into their cars and before long they got troubles - Joe