That knob is called a "Gorilla Knob". To start, turn the key to ON and pull the gorilla knob until you feel a little resistance and can see the idiot lights dim slightly. Hold at that positon until you see the GP indicator (salt shaker top looking thingy) above the steering column glowing. Pull a little further and she should fire off. I have to pull on mine for at least 45-60 seconds before I can see the glow in the dash indicator.

FWIW, in warm weather (>90°F) these engines generally don't need anywhere near that much glow time. On my 115 5-10 seconds usually will do the trick. If the engine is hot, I just yank it and go.

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Never a dull moment at Berry Hill Farm.