Mercury Marine’s first sweet taste of success in snowmobile racing carne in 1974, courtesy of its newest creation – the Sno-Twister.
The Sno-Twister – with its wide ski stance and heady Kohler twin engine – dominated the Stock D class on the United States Snowmobile Association (USSA) ovals circuit in 1974, including a complete sweep at the Eagle River World Championship in Eagle River, Wisconsin. It even helped convince top oval driver Stan Hayes to make the switch from Polaris to Mercury for the 1975 racing season.
This newfound success also persuaded Mercury to produce a trail version of the Sno-Twister – the Trail-Twister – for the 1975 and 1976 model years. Marketed as a high-performance machine for experienced trail riders, the Trail-Twister looked and acted like the stock D champ, but came with a less temperamental 440cc fan-cooled Kohler.
“Very definitely, the Trail Twister is a macho machine, designed after a highly successful stock racer, with the steady hand of experience required to attain peak performance,” Snow Goer editors wrote after testing the 1976 Trail Twister 440 in Colorado’s mountains.
Surprisingly, the outboard motor giant pulled the plug on its snowmobile racing effort during the 1976 season and ceased production of all its snowmobiles after that year. This came despite the Trail Twister’s strong reputation with consumers as a durable, performance-minded machine during its short-lived two-year stint on the snow.
High Performance First
Mercury offered the Trail Twister 440 for 1975, and added a 340cc-powered model to its fleet in 1976. The Kohler fan-cooled twin cylinder engines featured chrome-plated bores, which allowed the engines to run cooler and maintain power output at sustained high RPM. Dual Mikuni carburetors and a Wico CD ignition circuit were also standard.
A Y-shaped exhaust header angled down into a computer-tuned exhaust pipe. Designed by Mercury, these pipes helped tame engine noise, while also boosting engine performance. Paired with a set of Arctic Cat-built ramp-type clutches, the overall throttle response and top-end speed of the 440 was described by editors as “excellent.”
According to specs released by Mercury in 1976, the 340 pumped out 40 hp at 7000 rpm, while the 440 delivered 50 hp at 7000 rpm.
“The 440 performed outstanding on flat, hard-packed surfaces with a 70 mph top end through the quarter,” editors wrote. “[Its] acceleration through the eighth-mile [was] 11.3 seconds and in the quarter [was] 18 seconds flat.”
Mercury offered features on the Trail Twister that high-speed veterans would appreciate. The handlebars and throttle and brake Levers were adjustable so they could be set for individual preference and comfort. Its 6.2-gallon fuel tank aided in weight distribution. A mechanical disc brake mounted next to the chaincase brought the sled down from speed. Aluminum and fiberglass components helped keep the dry weight down. The chassis was aluminum and featured a strengthened engine bay.
The Trail Twister had the same 35-inch ski stance as the race-proven Sno-Twister. Its ski spindle angle was also pushed back 30 degrees – compared to other Mercury sleds – for better control and carving turns at full bore, according to a Mercury advertisement.
Though the wide stance aided the Sno-Twister’s cornering ability on oval tracks and added to the Trail Twister’s overall stability, it was a handicap for fast riding down a narrow trail where there was no room for error, editors said. “Heavy steering helps the skis carve racing turns, but gives sluggish response on the trail,” they wrote.
Unlike many slide-rail suspensions of the era that favored a single shock for damping the bumps, the Trail Twister featured one front track shock and two rear track shocks. Its front suspension was more conventional with shock-assisted leaf springs. For 1976, the shocks were recalibrated for better control of the springs.
Its three-layered foam seat was also ideal for mogul bashing, according to test riders. “Even pushing the machine fast down the deeply rutted portions of the Torture Trail couldn’t make the T/T bottom out,” editors wrote.
But Trail Twisters weren’t entirely all about performance; they were also practical for their time. According to editors, the Trail Twister’s mark of 24.9 mpg on an economy run in Colorado was only seven-tenths of a gallon away from the overall economy champ of 1976 – Massey Ferguson’s Whirlwind 440. “And second out of 26 sleds is outstanding,” editors wrote, “especially for a sled with the flat-out power and high performance image of the Trail Twister.”
Even with the performance image that the Trail Twister exuded, Mercury had faith in the sled’s durability. The Fond du Lac, Wisconsin, firm offered a one-year warranty on all components, including engine, clutch, drive and, get this, spark plugs.
“High performance buffs with more than a modicum of experience will find the Trail Twister a sled with exceptional performance,” editors said. “Under a veteran driver, the Trail Twister comes into its own.”
Editor’s Note: Every issue of Snow Goer magazine includes in-depth sled reports and comparisons, aftermarket gear and accessories reviews, riding destination articles, do-it-yourself repair information, snowmobile technology and more! Subscribe to Snow Goer now to receive issues delivered to your door 6 times per year for a low cost.