Below you will find the Snow Goer Test Report on the 1977 Scorpion Sting 440 snowmobile, as was originally published in the September 1976 issue of Snow Goer magazine.

 

Scorpion Sting 440

Is it fast? Yes! Is it brand new and well engineered? Yes! Is it expensive? NO!

1977 Scorpion Sting snowmobiel
1977 Scorpion Sting, as pictured in the September 1976 issue of Snow Goer magazine.

The Scorpion Sting, designed to hit hard at the sports enthusiast market, should do just that.

The Sting, featuring 15 percent more horsepower than the popular and agile Whip, respectable in its own right, is fast and decently competitive with any trail performance sled out there.

For example, in four acceleration runs through hard pack, packed and powder snow conditions, only two liquids and one free air outperformed the hefty fan-cooled Cuyuna which only has 428 actual displacement. Using the same engine as powers the Whip, Scorpion engineers were able to net that 15 percent more HP through muffling and carburetion. Maximum power band was also raised to 7100 RPM on the Sting versus 6700 RPM on the Whip.

The Cuyuna 428, the only engine offered in the Sting for ’77, is fueled by a single 38 mm Walbro float carb. The Sting, one of the boldest and most attractively styled sleds that we saw in Grand Portage, has a number of outstanding features that come together on the trail to make it an exceptional snowmobile.

The Cuyuna engine that we have demonstrated is fast, also gives the rider a real feeling of power right at his thumb. Listen to a couple of quotes from our three test riders.

“The engine power on this is just out of sight. It really turns on.” “It seemed like it was never going to run out of power.”

“The power on this machine just never seems to quit. It just seems to keep going up and up and up. It’s the most responsive engine that has ever been marketed under either the Rockwell JLO (its former name before Scorpion acquired manufacturing rights and

tooling from Rockwell) or the Cuyuna name.”

The powertrain throughout the Sting is close to excellent. Horsepower from that strong engine is transmitted to the track through the unique Power Thrust II clutch that shows marked improvement over the satisfactorily performing Power Thrust I. We tested six sleds at Grand Portage that featured the Power Thrust II clutch. All demonstrated the clutch’s ability to hold the engine RPMs on the power band under a wide range of conditions. In running acceleration tests through the eighth mile, for example, over both hard pack and 8-inch powder snow conditions, the Power Thrust II-equipped sleds needed very little more time to take the powder run than the hard pack. One sled needed only .6 of a second longer and another needed only one extra second. Of course, this is attributable to a number of factors – flotation, excellent traction under varying conditions, etc. – but the workability of the clutch plays a major role in any performance equation.

What the Power Thrust II clutch does is hold the engine RPM at its power band throughout changing snow conditions. For example, when you go from hard pack to soft snow, the engine loses very few RPM. The RPM curve is not a perfectly straight line under varying conditions, but it is quite close. The Power Thrust II achieved this through the use of a reverse ramp angle on the drive clutch. On conventional clutches, the drive and driven are essentially working against each other transferring power. But, with the reverse cam, the two clutches are working together to transfer power smoothly.

The Power Thrust II also has other consumer advantages over the Power Thrust I. The engagement speed can be changed, from say, 3200 to 4000 by changing one spring. On the Power Thrust I, six springs had to be changed. You can also vary top RPM for peak performance by changing a washer on the end of the weight arms.

Power isn’t all there is to talk about on the Sting, however. The suspension system with which our test Sting was equipped, the Para-Slide, also performs well and gives a decent, comfortable ride under most riding conditions. Scorpion gives buyers their choice of either Para-Slide or Para-Rail. The shock absorber-equipped Para-Slide features such a clean design and is so workable that we would recommend it over the time-prove Para-Rail that has been a Scorpion exclusive for years. We will qualify that recommendation, however. If you envision using that sled in marginal snow conditions, opt for the Para-Rail. Otherwise, go for the Para-Slide. Under most snow conditions, the ride of the slide is just as good and the agility in deep snow is better.

The Para-Rail Sting also features sound deadening cones on the 15-inch polyurethane track with fiberglass reinforcing rods. The slide tail equipped Sting uses a three piece track with two thirds cleated steel grouser flats.

For riders who do 40 percent or more of their riding at night the Sting has a major feature – a quartz halogen headline with 41,000 candle power. Scorpion continues to use magneto ignition systems when most companies are offering CDI on the performance sleds. But, Scorpion engineers state that they are satisfied with the output of the magneto. “CDI is not really that much more efficient and it’s dramatically more expensive to replace. We are able to get 150 watts out of our magnetos that’s quite satisfactory. It’s going to cost well over $100 to replace a CDI unit.”

What about overall trail riding comfort and characteristics? Excellent. We had some original concern about the length of seating area that the endure-style seat permitted. But, since our spring tests, Scorpion has made significant changes and the Sting now offers a full 31 inches from the footrest to the beginning of the backrest high-rise. The new seat is also contoured both vertically and horizontally to contour naturally to the rider’s back.

With its front-mounted engine and 29 1/8-inch ski stance, the Sting is stable and easy steering. At 390 pounds wet, the Sting is extremely light. Only the Whip was lighter of the full-sized machines tested at Grand Portage.

Viewed as a total machine, the Sting is an excellent machine that fills a needed void in the Scorpion lineup, fitting neatly between the Range Whip 400 and the family-oriented Whips. Its introduction is an excellent step for the Crosby, Minnesota, company.

 

SCORPION STING 440

Suggested retail price: $1,695 + tax and duty

ENGINE/DRIVETRAIN

Engine position: Front mounted.

Manufacturer: Scorpion Cuyuna

Displacement: 428cc

Cylinders: 2

Cooling: Fan

Compression ratio: 13.2: 1

Bore/Stroke: 2.657 inches/2.362 inches

Carburetor: 1 Walbro

Drive Clutch: Power Thrust II

Driven Clutch: Scorpion

VITAL STATISTICS

Weight: Wet, 390 pounds, Dry 358.5 pounds

Fuel Capacity: 5 U.S. gallons

Length: 102 inches

Width: 36 inches

Height: 29 inches without windshield

Ski Stance: 29 1/8 inches

SUSPENSION/TRACK

Suspension Type: Para-Slide or Para-Rail

Suspension Damping: Single adjustable shock in rear

Ski Suspension Type: French leaf spring

Ski Damping: Shock

Track Length (on ground): 34.5 inches

Track Width: 15

Track Material: Polyurethane with fiberglass reinforcing rods

GENERAL INFORMATION

Brake Type: Drum with self-energizing shoe

Brake Mounting: On driven clutch

Chassis Material: Aluminum and steel

Ignition Type: Magneto

Instruments: Standard speedometer, tach

 

 

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