Cosmo Sport (110S)

1967-1972 / Coupe / Japan

All Cosmo Sport (110S) problems All workshop issues

Common Ignition System

Points and Condenser Degradation

Symptoms

Misfiring, rough running, difficulty starting, inconsistent idle.

Cause

The original ignition system uses contact breaker points and a condenser. These are wear items that require regular adjustment and replacement, something that was routine maintenance in the 1960s but is often neglected today. The points pit and corrode, the condenser fails, and the spark becomes weak and inconsistent.

Fix

Replace points and condenser as a starting point.

For reliability, many owners fit an electronic ignition module (Pertronix or similar) inside the original distributor housing.

This is invisible from the outside, fully reversible, and eliminates the need for points adjustment.

Cost: $100-200 for a Pertronix kit.

Cost mentioned in fix

Cost: $100-200 for a

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Other known issues

Minor Ignition System

Spark Plug Fouling

Misfiring, rough idle, loss of power. Plugs come out with heavy carbon or oil deposits.

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 Fuel System

Carburettor Deterioration

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

View all 10 Cosmo Sport (110S) problems