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1968 Ski-Doo 600 T'NT

First Rotax twin set course for future sleds, industry
EXPLOSIVE - In 1968 Ski-Doo launched the T'NT as a race sled, but its vertical twin 599cc engine blew the roof off engine expectations in the marketplace. The one-lungers were about to become extinct.
Bill Fullerton photos
Note: the roll-away headlight, side air scoops and aerodynamic lines too.
Back in the day, one-lunger snowmobiles were the norm and horsepower was something folks associated with, well, horses.

Ski-Doo, marking its 50th year this season, changed things up in 1968 when it powered up the industry with its T'NT 600 for racers and its first vertical twin, packing 35 horsepower. The engine also was Rotax's first that was specially designed for a snowmobile, as earlier powerplants were adaptations of industrial engines, mostly water pumps.

Canadian Bill Fullerton was just 13 when he first saw a 1968 T'NT at a neighbor's house in Port Sydney, Ont. That neighbor was Rick Clarke, a racer and later race director for Bombardier in Ontario.

"He told me, 'If you can start it, you can ride it.' Well, I ended up with two bloody noses, but I got it started," says Fullerton, who owns what vintage experts say may be the best example of a '68 T'NT in the world.

There weren't that many to begin with. Built strictly for racers and shipped to dealers for the 1968 race season, sled historian Phil Mickelson says only 117 were made. Fullerton believes even less than that, maybe as few as 50, and less than a dozen are known to still exist.

This rare breed was to be sold only to racers and then returned to, and sold back to, the dealers or distributors, Mickelson says, and he has the paperwork to prove it. Ski-Doo's parent, Bombardier, worried that competitors would get their hands on the 600cc engine and copy it.

Seems like a reasonable worry, especially after Steve Ave won the 1968 Eagle River World Championship Derby aboard one.

Bulked up
Ski-Doo's T'NT, which stood for Track 'N Trail, rode on a modified Super 370 chassis that had been strengthened to hold the new beefier engine. There was an angle iron in the engine mount area, stronger ski legs and a spreader bar in the back to strengthen the tunnel.

Mickelson says the driven pulley also was reinforced and the drive axle was solid instead of hollow. The chaincase was also bulked up and offset to the left.

Helmut Roteh was the designer of the 600 as head of Rotax's R&D department. It was an axial fan cooled design with the fan mounted at cylinder level and driven by a V-belt from the flywheel. The 599cc engine had a bore of 2x76mm and stroke of 66mm, creating 35 hp at 6,000 rpm in stock form and 45 hp at 6,800 rpm when modified.

Originally, it was fitted with an intake manifold that mounted a Tillotson HR and a Tillotson HD carburetor. A progressive linkage controlled the opening of the carbs.

T'NTs set the stage for all 2-cylinder engines and sleds to follow, Fullerton says, and set high styling marks too. Its windshield was angled the same as the hood for a sleek aero look and its designer, Sam LaPointe, came up with the Black Dot headlight, a retractable light set in a black dot on the sleek hood.

There also were fiberglass air scoops on the body's sides and a black stripe that gave it a trim, racy look, especially combined with the Black Dot headlight. The seat was leaner too with no seat-back, just a hump.

After its successful racing debut, Ski-Doo followed in 1969 with T'NT 399 and 669 models, boasting 30 and 45 horsepower, respectively. Customers snatched them up like they were going out of style.

Finding one
How did Fullerton land his T'NT? Perseverance and luck!

He started by collecting parts. While working for Ski-Doo's Sno-Pro race team in 1977 he bought a hood, seat, windshield and two manifolds from Ski-Doo's surplus store in Valcourt, Que. Years later his quest led him to Saskatchewan, where a parts guy at Mercury Service in Moose Jaw gave him a broken hood, netting him two air scoops. That was in 1981, but it was 10 years later that the same parts man alerted him that an area farmer had the remainder of the sled and gave Fullerton the man's phone number. The farmer confirmed he had the machine, but said it was owned by Doug Catling, who owned Mercury Service.

Fullerton said that through the years Doug always told him he didn't have time to deal with old equipment, but a few years later Catling called to get 10 extra Sea-Doo XP watercraft from Fullerton and sent a truck from Saskatchewan to pick up the load.

When the driver got to Fullerton's warehouse he asked Fullerton to help unload a crate before they put the Sea-Doos on the truck. Surprisingly, the crate held the old T'NT with a hand-written note saying "I don't know why you want this, but it's yours. Now send me my Sea-Doos."

Fullerton's sled is amazing and he did the restoration himself. He's proud of it too, and the shiny machine still sits in a spare office at his Bracebridge facility, two hours north of Toronto.

"The T'NT really stood out from everything else out there," Fullerton says, and you can hear the smile in his voice.
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