Inspect enclosure louvers for dirt and debris
Inspect lines and connections for fuel or oil leaks
Check engine oil level
Inspect for water intrusion
perform fuel system leak test
Check battery condition, electrolyte level, and state or charge
Replace engine oil and oil filter
Replace engine air filter (if needed)
clean; inspect spark plug gap; replace if necessary
Inspect/adjust valve clearance (where applicable)
Inspect/clean sediment trap (where applicable)