Rev. Rul. 58-186

The manufacturer of a power lawn mower also produces a `sulky,' which is a four-wheel cart having a seat and its own engine. The `sulky,' when attached to the power lawn mower, can be used as a riding mower, in which event the mower and `sulky' are both powered by their own individual engines. Other equipment, such as a grass sower, fertilizer attachment, lawn roller, etc., can also be used with the `sulky.' Held, the `sulky' is not a part or accessory for a power lawn mower. Accordingly, sales of the `sulky' by the manufacturer are not subject to the manufacturers excise tax on power lawn mowers imposed by section 4121(a) of the Internal Revenue Code of 1954 regardless of whether it is sold separately or on or in connection with the sale of a power lawn mower, provided it is billed separately on the manufacturer's invoice or the price thereof can be readily determined from his records.