In oil-cooled engines like the Apache RTR 200 and Pulsar 220, the cooling system typically does not include an oil pump to circulate the oil to a separate radiator and back.
In these motorcycles, the oil cooling is achieved through the engine's internal passages and fins, which help dissipate heat. The engine oil flows through these passages and comes in direct contact with the engine components, absorbing heat and carrying it away. As the oil circulates through the engine, it transfers heat to the surrounding air, which cools the oil.
While some motorcycles may have additional external oil coolers, they usually rely on the natural flow of oil driven by the engine's internal oil pump. The oil pump is responsible for lubricating the engine's moving parts and maintaining proper oil pressure, but it is not specifically designed to circulate oil to a separate radiator.
It's worth noting that liquid-cooled engines, on the other hand, employ a separate cooling system that uses coolant (typically a mix of water and antifreeze) to carry heat away from the engine. These engines have a dedicated water pump to circulate the coolant through the engine and to a radiator where heat is dissipated before returning to the engine.