Engine hesitation and poor power are caused by incomplete combustion (Incomplete combustion would be caused by abnormal spark plug), and therefore fuel consumption is affected by spark plug condition.

3.

Check the spark plug condition and electrode gap.

A.

Specification : 1.0 - 1.1 mm (0.039 - 0.043 in.)

4.

Are spark plug condition and electrode gab normal?

YES

Spark plug is OK

NO

Adjust electrode gab the spark plug and Replace the spark plug.