a snowmobile shown generally at 10 is of standard construction having front steering skis 11 , mounted onto a chassis or frame 12 , and which has handlebars 13 for steering the skis . an instrument cluster 14 is adjacent to the handlebars , and a hood member 15 that comprises an engine compartment cover , and also mounts the windshield 16 is mounted in a suitable manner with hinges to the forward portion of the chassis or frame 12 . this hood member will lift up , and when it is lifted up the side portions of the machine on opposite sides of the instrument cluster will lift up with the hood member to expose the engine and parts below . the engine 17 , which is indicated schematically , is mounted in a suitable manner under the hood , and the engine has an air intake port or connection 18 . this air intake port is a cooling air intake which provides for a flow of cooling air across an air - cooled engine . the volume of air across the engine is controlled by the fan size and by the cross - sectional size of the intake port on the engine . constriction of the cross - sectional area any place along the intake connection will constrict the airflow . thus , it is important to have at least an area equal to the intake port of the engine in all places along the intake conduit . the air intake port 18 as shown is connected through a flexible coupling 19 to a combined tool box and intake duct assembly 22 made according to the present invention . the assembly 22 is a unitary , molded pipe that has a first circular pipe portion 23 that is formed as an elbow , and a rearwardly extending main body portion 24 . the duct may be molded from suitable plastic material . the transition area between the main body 24 and the pipe portion 23 can be molded and formed in a desirable manner to provide for smooth airflow between the two portions . as shown , the main body portion has a transverse width indicated generally by the arrows 25 , 25 which is greater than the diameter of the intake port 18 , and also the main body has a substantial vertical depth , as shown in fig4 . this additional width can be accommodated because of the spacing between the center portion of the tunnel of the machine indicated generally at 26 , and the side portions of the machine . normally , when a conduit that is tubular and of circular cross section is placed in this location , there is some waste of space , but not enough extra space to accommodate a separate tool box . the main body portion has a top wall 27 , and vertical or uprightly extending side walls 28 that are spaced part . the side walls 28 connect the top wall to a bottom duct wall 29 that is substantially planar , and rests along portions of the frame 12 of the snowmobile . the top wall 27 , as shown , has a center cavity 31 defined therein , and the cavity is formed by end walls 32 , 32 , side walls 33 , and a bottom wall 34 . the cavity has an open top when viewed in relation to the duct itself , but the walls 32 , 33 and 34 form a receptacle isolated from the interior of the main body of substantial vertical and transverse depth . air is permitted to pass or flow between the walls defining the receptacle and the walls form the main body portion 24 . also as shown , the upper wall 27 may be provided with a molded receptacle 37 for a spark plug wrench , a transverse receptacle 38 that is shaped so that two spark plugs can be laid end to end in it and a receptacle 39 that can be used for the actuator lever for the spark plug wrench placed into the receptacle 37 . as shown perhaps best in fig3 a cover member 40 which is also molded from suitable material is made to fit over the center portions of the body 24 and to cover the receptacles defined in the main body . as shown in fig3 the center part of the top wall 27 is raised , and the cover 40 has a flange 41 that fits over the sides and ends of this raised portion . in addition , the cover 40 has a pair of molded integral ears 42 that are positioned on opposite sides of a transitional throat 43 leading to the curved pipe section 23 . these ears 42 are pivotally mounted with suitable pins 43 to the transition section , so that the cover 40 can be raised and lowered about the axis of pins 43 to permit access to the cavity 31 . a suitable lock 45 may be provided for securely fastening the cover in place with respect to the top wall 27 . the end 50 of the main body portion 24 is open , and a grill member 51 can be used for covering this opening . the grill is positioned adjacent an operators foot support 51a that is alongside the forward end of the tunnel 26 which forms part of the frame . the opening provides the air intake for the duct , and the major portion of the air taken in will strike wall 32 and be deflected downwardly and sideways to flow around the tool box . this provides a change of direction for a substantial part of the incoming air to reduce the noise level . as the air reaches the transition throat 43 the bottom wall 29 is sloped upwardly as at 29a so the air flowing under the tool box must change direction . note that wall portion 29a extends upwardly to a level above wall 34 of the tool box . again noise is reduced . as shown in fig2 the air flowing along the sides of the tool box walls also must change direction again before it flows through the intake part of the engine . thus substantially all the intake air is caused to change direction at least once , utilizing the baffles formed by the tool box walls , to muffle the noise generated . the tool box walls also perform the second useful function of holding necessary tools , as well as serving as baffles . the unit is easily molded , low cost , and combines the functions of providing a noise reducing muffler for intake airflow and a safe , secure tool box in the air intake duct for the engine without unduly complicating the construction , raising the cost , or taking additional space other than that which is already present on the snowmobile frame construction .