. OPERATION MACHINE OPERATIONS AND CONTROLS STOPPING THE ENGINE NOTICE gradually. 3 - 61 If th e engine i s stopped abruptly, servic e life of component parts of the engine may be considerably redu ced. Hence do not stop the engin e abruptl y except in an e mergency. I f the engine has overheated, do not try to stop it abruptly but run it at medium speed to a llow i t to c ool down gradually , and t hen s top i . Run the engine a t low idling for abo ut 5 minutes to cool down . Turn the key the engine. . Remove the key from starting s witch (1) tarting s witch (1) to the OFF position to stop