Here is some information on identifying your Snapper Comet.
My Snapper comet riding mower information
My snapper comet 26 model: 265xs serial number: 557685
The first digit in the serial number (5) is of the year. So my comet is a model year 1965. My mower has a loop steering post and those were replaced in 1974 with a bicycle handle bars. So it would appear that mine is a 1965 Model. This year 2016, the riding mower is 51 years old. The loop handle bars continued through 1973. In 1974 the loop was replaced with bicycle handle bars through 1985 and loops on the front of the deck continued through 1984. In 1980 the bicycle handlebars had a black triangle at the top of the handlebar post. Steering wheels replaced the handle bars in 1986.
The Tecumseh id number is stamped on the front of the engine cover. My engine Tecumseh tvxl195 150221 9335D (Original engine Tecumseh V50 60200V 5HP)
My engine Tecumseh tvxl195 150221 9335D Dec 1, 1999 19.43 CI/318.46 CC= 8 HP
CRAFTSMAN TO TECUMSEH CROSS REFERENCE 143.406092 TVXL195-150233
9335D is the serial number or D.O.M. (Date of Manufacture)
9 first digit is the year of manufacture (1999)
335 indicates calendar day of that year (335th day or Dec1, 1999)
TVM & TVXL 170, 195, 220; OVM 120; OVXL120, 125 oil 32 OUNCES
Spark plug RJ17LM
Number designations following the letters indicate the horsepower or cubic inch displacement.
The number following the model number is the specification number. The last three numbers of the
Specification number indicate a variation to the basic engine specification.
The serial number or D.O.M. indicates the production date.
150221 is the specification number used for properly identifying the parts of the engine
9335D is the serial number or D.O.M. (Date of Manufacture)
9 first digit is the year of manufacture (1999)
335 indicates calendar day of that year (335th day or Dec1, 1999)
C represents the line and shift on which the engine was built at the factory.
Spark Plug Champion J8c Replaces Autolite 295, Bosch W9eco, Ngk B6s, Nippondenso W20s