Possible Cause

Possible Remedy

Improper fuel (gasoline) in tank

Drain tank, flush system, fill with proper fuel

Tank empty or tank vent blocked

Fill tank/bleed system, check tank vent

Air in the fuel system

Bleed fuel system, eliminate air leaks

Fuel filter blocked

Replace fuel filter

Fuel-supply lines blocked-resticted

Test all fuel supply lines - flush or replace

Paraffin deposit in fuel filter

Replace filter, use winter fuel

Pump-to-engine timing incorrect

Readjust timing

Overflow fitting interchanged with inlet fitting

Install fittings in their proper positions

Cold-start device malfunction

Check cold-start mechanism

Low or uneven engine compression

Repair as necessary

Fuel injection pump defective or cannot be adjusted

Remove pump and service