What is the difference between a liquid-cooled engine and an air cooled-engine?
A liquid-cooled engine gives you a constant operating temperature which will increase fuel economy, decrease oil breakdown, and may last up to 50% longer. In addition, a cooler engine also means a cooler operator because the cooling fan draws hot air through the radiator, past the engine and away from the operator.
An air-cooled engine is much simpler with fewer working parts which means a lower purchase price and less maintenance.