For some people, the allure of late 1990s “triple-triples” is just too strong to ignore. The snarling beasts dominated laketop grudge matches and made racing heroes shine brightly under the lights at big-time oval races.
The big displacement “musclesleds” like the Thundercat, Mach Z, Vmax-4 and Storm were the obvious choices for people chasing the fastest speeds, but there was also a fascinating undercard – the 600-class triple-piped triples that made about 130 horsepower, and did so with a cool sound and mighty attitude. Arguably the best of the bunch was Ski-Doo’s Formula III 600.
Unveiled to much fanfare at the now-defunct Minneapolis Snowmobile, Ski & Winter Sports Show on November 7, 1994, the 1995.5 Formula III was named after the oval racing class it was built to win. It boasted a new, 598cc liquid-cooled, reed-valve triple, fed by a bank of Mikuni VM36 carbs and featured then-industry-exclusive RAVE variable exhaust valves.
That engine package was placed in the F-2000 chassis, with a DSA trailing arm front suspension and the Triple Shock C-7 rear. To make it’s new “purple screamer” race-legal, Ski-Doo had to build at least 500 of them, and that’s the exact number they assembled the first year – with some going to race teams and the rest scattered to dealers as demo models.
For 1996, the Formula III 600 moved into full production. The engine wasn’t quite as powerful as the racing-focused, limited-build 1995.5 sled, but it was still a rocket. For its sophomore year, the sled got flatter footrests, a new air intake, chromoly sway bar, billet aluminum steering arm and updated clutching. An LT version was available with a 136-inch track.
Then Ski-Doo began efforts to improve the ride quality of its triple-piped triples, and that led to differing opinions in terms of which F-III 600 model is best. For 1997, the C-7 rear suspension – which was renowned for its weight transfer and stability but not for its bump-absorbing abilities – was dumped in favor of the semi-coupled SC-10 skid, and travel was also added up front. Handling and bump capability improved, but some speed was lost in the process.
Significantly larger changes came in 1998, when all Ski-Doo triples moved to the new CK3 chassis, which featured new bodywork that was 4.5 inches narrower, enabled in part by a redesigned exhaust system that had the pipes wrap over the top of the cylinders. The sleds were quieter, featured more suspension travel and looked more modern, but first-year Formula III 600s in the CK3 chassis were plagued by electrical problems, heat management issues and were known to seize their center cylinder. They were also slower.
The CK3 sleds did provide a better ride, however – particularly the 1999 model that had better skis. By then, though, the triple-triple craze was coming to a rapid end as consumers switched quickly to lighter, more agile torquey twins, and 1999 would be that last Formula III 600.
Bottom line: When shopping for a used Formula III 600, determine your priorities. If having a fast triple-triple is most important, the 1996 model is the diamond; if handling and ride quality are higher on your list, however, a 1999 model is the sweet spot.
When browsing on the used market, pay particular attention to items that tend to decay over time, according to used sled aficionado Todd Guthrie of Dyna-Tek Performance in Angola, Indiana.
“You’re talking about a 20-year-old sled, so rusted-through pipes and rotting carb boots are something to look for,” Guthrie said. “Also the fuel line in the tank could be rotting off, check out the condition of the shocks and clutches – really, with a sled that old, you’ve got to do a front-to-back inspection.”
The engines, though, proved to be very solid over time except for that 1998 model, Guthrie said. Aside from checking on the center cylinder in particular, Guthrie noted that the steering arm rubbed on the CDI box, causing various problems.
Overall, the 1999 model in the CKS was the best trail version of the F-III, he noted.
“I think the CK3 chassis was probably worth it on the trails, but you give something up on top-end speed,” Guthrie said.
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