Why does my John Deere mower motor stumble?

Just a standard 17.5 E100. Bought it with 5 hrs. on it. Since day 1 after about 15 mins. it starts to misfire and stumble. Changed plug twice. Only ever use fresh 87 gas. Changed fuel filter. Tried Tru Fuel. Seemed to help but still. It's weird.

Sometimes it never does it but more often than not it does.

5 Answers

  • 1 month ago
    Favorite Answer

    Try checking the fuel tank vent. If this is obstructed it can lead to a partial vacuum forming in the tank which will restrict the flow of fuel. Sometimes it takes a while for sufficient vacuum to form to do this, then after the engine has stopped enough air manages to seep in to let it go on again for a while.

    (The vent is often simply a small hole in the fuel cap, it only takes a little dirt to bung this up.}

  • 1 month ago

    Sounds like it's a little rich on mixture, but I am unfamiliar with that type of carb. 

  • 1 month ago


  • 1 month ago

    Take the carb bowl off and clean out the bowl and jets.

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  • 1 month ago

    Check the air filter.  Either clean or replace.

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