By Les Pinz
In 1971 other snowmobile manufacturers had cool names for their high-performance snowmobiles. Ski-Doo had the TNT—Track ‘n Trail. Polaris came with TX—Trail Extreme. So Cat came up with EXT—Exterminator. This is what I was told back in the day. Very cool names with a lot of history.
In 1969 Arctic Cat started an alliance with Japanese engine builder Kawasaki to supply snowmobile engines for different applications. Arctic Cat wanted a lightweight twin that made good horsepower for its size and used the same crankcases to make it more simplified for parts availability. It used the same crankcase on twin cylinder free air and fan-cooled models. Kawasaki engines came in nine different sizes—from the 292cc to a big 4-cylinder 800cc in the King Kat.
During the 1971 model season Arctic Cat made more then 74,000 snowmobiles. Models included the Lynx, Puma, Panther, EXT, EXT Special and King Kat.
The EXT was made off of the Puma chassis which came with a 17-inch-wide rubber belted cheated track with about 30 inches on the snow. The EXT was 30 inches wide from outside ski to outside ski. It had slide rail suspension for a better ride and more speed. It was built with a redesigned hood with a large opening so the large finned free air engine could stick out of the hood so it would stay cool when racing. It also had an easy tilting hood so it was easy access if you needed to work on the engine and components.
A CDI ignition with lighting coil was standard for better performance and reliability. Twin Walbro carburetors came standard for peak power. Some EXTs came with mufflers and others had tuned cross-over pipes. You could even get from the factory a two-into-one alternate exhaust system kit that came with a wiener-like muffler that went along the right side under the hood. Did it help? It sure looked cool … and there are not many around.
EXT came with Salsbury 7R drive clutches before Cat made its own. The driven clutch had a lip extended toward the chain case so the brake pucks could clamp down on that lip to stop the sled. They were okay but could have been better for racing. It had the same steel bulkhead as the Puma.
Arctic Cat had a center-mounted 4.5-gallon fuel tank with lightning bolts formed into the top of the tank. The seat came with a leopard design in the cover and was tapered toward the front with the fuel tank between your legs. Plus there was a storage compartment in the rear of the seat. Footrests were located on the running boards and were about five inches tall to prevent your feet from getting burnt on the pipes. These footrests were held in place with pop rivets through the running boards.
The EXT handlebars were kind of an ape type that looked cool and rode nice but were hard to handle when racing. Many racers switched to Panther bars that were straighter to make it easier driving when racing. There were two kill switches—one mounted next to the throttle and the other on the console. (Back in the day we had a lot of ice and snow freezing on the carburetors that would make them stick open … so the added kill switch came in handy.) The speedometer read up to 100 mph and was mounted in the center of the console with a purple and green background for a great look. (You never went that fast … but it was impressive to think you had visual evidence if you did.)
The EXT weight was listed at 290 pounds. Its price was listed at $1,095 for the 295cc and up to $1,250 for the 436cc. There were over 1600 EXT snowmobiles made in 1971 in all four sizes.
Cat also made some EXT Specials in 1971. They featured the King Kat track and suspension at 15 inches wide with different drive sprockets. The tunnel was a little longer and track was 116 inches long. It also came with galvanized skis along with a chrome fuel tank. The seat was the same as the King Kat and featured a large hump on the back to allow you to lock in place. The EXT Special had an aluminum bulkhead to make it lighter, but it was a little weak and frequently broke.
The EXT Special came in 292cc, 340cc, 399cc and 440cc engine packages. There were 463 EXT Specials made in 1971.