FAQs

It is necessary to run an air cooled engine at its highest rpm for the following reasons:

A) The engine’s cooling and lubrication systems are designed to operate best when the throttle control is in the highest position. Running the engine at a lower speed will decrease the flow of cooling air and the volume of oil circulated. These two factors will shorten engine life

B) The engine’s carburetor is adjusted so that the engine operates most cleanly and efficiently at full throttle. Operating outside or below the optimum speed range for the engine and carburetor produces less power

C) Everything driven by the engine (eg. cutting deck) is designed to turn at the speed maintained by the engine’s governor when the throttle is at the highest position. Running the engine at a lower speed will result in lower performance and excess vibration as well as increased wear and tear on the various drive components (e.g. cutting deck drive belt)

D) Models equipped with engines that have DC electric starters and battery systems and have engines that recharge the battery may result in poor battery recharge rate if the engine is not operated at full RPM. These engines have stators that produce recharge electrical current to the battery circuit only when properly tuned and operated at full RPM. Most frequently the report of poor battery recharging can be traced to customers that do not keep the throttle at full. On tractors, and other self-propeled units, the engine should be kept at full throttle whenever possible and the ground speed should be regulated by shifting into a lower gear or using the ground speed control. Do not use the engine throttle to regulate ground speed or the battery will not get sufficient electrical current to maintain charge.