Description

This series of engines are usually to be found on large walk behind rotary lawnmowers, although some small rotorvators, generators and other equipment
needing a vertical crankshaft also use them.

The Mk1 Quantum was manufactured between 1988 & 1989 and is distinctly different to the Quantum series manufactured after this date.
The Mk1 is quite a rarety to see nowdays.
Some parts are common to both versions.

The Mk1 Quantum has its oil filler dipstick mounted centrally along the back edge of the engine, whereas all other Quantums have their dipstick
at the left rear corner

All Quantums are side valve with the spark plug in the centre of the cylinder head cooling fins.

The plastic fuel tank wraps around the engine with the fuel cap towards the rear right.

Some have a primer for cold starting mounted to the front of the air filter base, some have ready start (automatic choke controlled
    by means of a thermostat mounted behind the exhaust and some have a traditional choke operated by the throttle cable.

Above the carburettor is a plastic cannister which hold the air filter cartridge

The Model, Type and Code numbers of most Quantums are stamped into the engine's pressed steel cover just above the spark plug location, or on a pressed steel plate over the exhaust.
    Some have further plastic top covers which may need removing or pushing up slightly in order to see them. The model number begins with 12

The Mk1 has its Model Type and Code numbers etched into its plastic cover/fuel tank just above the spark plug location, it model begins with 10.