et al and u s pat no 5 048 503 by k suzuki and y yurzuriha all of which are herein incorporated by reference referring to the figures a two cycle engine 1 for a snowmobile is shown wherein the engine includes a cylinder 2 of the engine 1 having an intake port 2a and an exhaust port 2b a spark plug 4 is located in each combustion chamber formed in a cylinder head 3 a crankcase temperature sensor 6 is provided in a crankcase 5 water jackets 7 are provided in the crankcase 5 cylinder 2 and the cylinder head 3 the intake port 2a is in communication with an intake manifold 9 through an insulator 8 a throttle valve 9a is provided in the intake manifold 9 a throttle position sensor 10 is attached to the intake manifold 9 a fuel injector 11 is provided in the intake manifold 9 adjacent to the intake port 2a the intake manifold 9 is in communication with an air box 12 having an air cleaner not shown an intake air temperature sensor 13 is mounted on the air box 12 fuel in a fuel tank 15 is supplied to the injector 11 through a fuel passage 14 having a filter 16 and a pump 17 the fuel injector 11 is in communication with a fuel chamber 18a of a pressure regulator 18 and the fuel tank 15 is in communication with an outlet of the fuel chamber 18a a pressure regulating chamber 18b is in communication with the intake manifold 9 the fuel in the tank 15 is supplied to the fuel injector 11 and the.