GC is one of the short codes used in the catalogue to file engine manuals that are identified by model code rather than by brand name. It does not stand for a specific manufacturer; the heading simply collects service material for engines whose model numbers begin with GC. The code itself usually appears stamped on the engine shroud or cooling cowl.

To use these manuals correctly, find the engine identification plate or stamped code on your equipment and write down the complete model number. Engine codes of this style are common on small air-cooled engines fitted to mowers, generators, pumps and similar machines. Mowers, pressure washers, pumps and small generators are typical machines that carry this style of engine code.

The workshop manuals filed under GC cover standard engine service work: cylinder and piston overhaul, valve adjustment, carburetor and fuel system service, ignition and starting systems, torque specifications, adjustment data and scheduled maintenance intervals. Clearances, torque values and wear limits are laid out so that even a straightforward service can be carried out to the maker's original standard.

Small-engine owners and repair shops will find these manuals practical once the exact engine code is confirmed, because they provide the specifications needed for dependable and accurate repairs. If the exact manual for your engine cannot be found under GC, try searching by the machine brand or the full engine code, as the same engine often appears under several headings.