Briggs and Stratton 18.5 twin ii issue

[johniii]

HI,I bought a used Quality farm and country rider.Looks like it had been sitting for awhile.Started right up and then after running for awhile it started acting like it was out of fuel and I would top off the tank.I decided to change plugs,air cleaner and oil.Then it got progressively worse.I changed the cruddy gas filter.Still running like crap,the engine speed goes up and down ,it is not bad at slow idle but crank it up and it keeps surging .It is worse with a load on it.I sprayed some carb cleaner but haven't removed the carb. The up and down of engine is consistent,it goes up then bogs down,surging bad..I have also blown out the fuel line from filter back into tank and also the gas cap.I haven't drained the fuel tank,don't know how old the gas is.Any clues??

 

[chance123]

It's best to drain the tank, new fuel filter, drop the float bowl and clean the main jet.

 

[Rivets]

Don't just drop the float bowl, remove the carb and give it a 24 hour soaking or have it ultrasonically cleaned. Reassemble with a new needle and seat, plus new gaskets.

 

[Rokon]

Started right up and then after running for awhile it started acting like it was out of fuel and I would top off the tank...I changed the cruddy gas filter.Still running like crap,the engine speed goes up and down ,it is not bad at slow idle but crank it up and it keeps surging .It is worse with a load on it.I sprayed some carb cleaner but haven't removed the carb. The up and down of engine is consistent,it goes up then bogs down,surging bad..I have also blown out the fuel line from filter back into tank and also the gas cap.I haven't drained the fuel tank,don't know how old the gas is.Any clues??

Problem we see around here: Ethanol fuel can go bad in as little as two months.

Completely drain the tank, lines, and clean the carb. Run some Seafoam engine treatment through on the first tank as well.

 

[RussellTP]

I put super unleaded gas in riding mower to clean out the entanol. :wink:

 

[Brucebotti]

I put super unleaded gas in riding mower to clean out the entanol. :wink:

All grades of gas in CT have ethanol in it. Is it different in NC? Just curious.

 

[chance123]

I put super unleaded gas in riding mower to clean out the entanol. :wink:

Here in Southern California, super unleaded means there is even "more" ethanol in the ratio of fuel.

 

[johniii]

Pulled tank and cleaned,pulled carb and cleaned,it looked like new,no gunk. I used carb cleaner and blew it out. Also did seafoam treatment. Runs like new,no hesitation. Thanks for the help.