Cosmo Sport (110S)

1967-1972 / Coupe / Japan

All Cosmo Sport (110S) problems All workshop issues

Critical Fuel System

Fuel Line and Tank Corrosion

Symptoms

Fuel leaks, restricted flow, debris in the fuel system.

Cause

Steel fuel lines corrode from the outside (road spray, moisture) and the inside (ethanol-blended fuels attack older materials). The fuel tank corrodes internally, producing rust particles that clog the carburettor and fuel filter.

Fix

Inspect all fuel lines, replace any corroded or cracked lines with ethanol-compatible hose and fittings.

The fuel tank may need to be removed, cleaned, sealed (POR-15 or similar tank sealer), or replaced with a custom-fabricated unit.

Fit an inline fuel filter between the tank and carburettor.

Cost: $200-500 for lines and filter; $500-1,500 for tank restoration.

Cost mentioned in fix

Cost: $200-500 for lines$500-1,500 for tank

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// More Cosmo Sport (110S) problems

Other known issues

Common Fuel System

Carburettor Deterioration

Poor idle, flat spots during acceleration, fuel leaks, difficulty starting, rich or lean running.

Minor Engine, 10A Twin-Rotor (982cc)

Apex Seal Wear

Loss of compression, reduced power, difficulty starting (especially when cold), blue-white exhaust smoke, and eventually misfiring and inability to idle. A rotary engine with worn apex seals is an engine that needs a rebuild, there is no halfway measure.

Common Engine, 10A Twin-Rotor (982cc)

Hard Cold Starting

The engine cranks extensively before firing when cold. May require multiple attempts. Once warm, starting is normal.

Minor Engine, 10A Twin-Rotor (982cc)

Oil Metering Pump Failure

Without lubrication, the apex seals run metal-on-metal against the rotor housing. Wear accelerates catastrophically. The engine may seize.

Critical Engine, 10A Twin-Rotor (982cc)

Cooling System Inadequacy

Engine overheating, particularly in traffic or on hot days. The temperature gauge climbs steadily, coolant may boil over, and in extreme cases the engine suffers heat-related damage (warped housings, blown coolant seals).

Common Ignition System

Points and Condenser Degradation

Misfiring, rough running, difficulty starting, inconsistent idle.

View all 10 Cosmo Sport (110S) problems