A snowmobile provided comprises a chassis including a tunnel, an engine disposed on the chassis at a forward end thereof and a seat disposed on the tunnel behind the engine. 001 to 1 part by weight of at least one antioxidant selected from compounds of formula :wherein R1, R2, R4 and R5 independently represent hydrogen, C1-8 alkyl, C5-8 cycloalkyl, or the like, R3 represents hydrogen, C1-8 alkyl, or the like, X represents a single bond, or the like, 0. The first dye frame of each dye region is registered after each black bar region is detected. The assembly apparatus includes spacer nests proximate to the assembly nests for assembly of spacers between the opposed magnetbackiron assemblies. In one aspect, the invention also relates to a combination for a water heater comprising a top cover and a bottom tray, and in another aspect to a bottom cover for a wall mounted water heater.