How Can I Add Horsepower to My 2007 Arctic Cat 660 4-Stroke Engine?

The Arctic Cat 660 snowmobile with a four-stroke engine is generally regarded by enthusiasts as a reliable, stable machine more often used for touring rather than racing. It is heavy at 620 lbs. dry weight. The standard four-stroke engine produces 53 horsepower. The weight helps give it stability and comfort, but also slows it down. Engine modifications produce the biggest boost in horsepower, but you can also increase power by reducing weight, modifying tracks and using high-performance oils and lubricants.

Instructions

    • 1

      Install either a turbo-charger or a supercharger to your engine. The companion to the Arctic Cat 660, the T660 comes with a factory-installed turbo-charger that gives the same engine 110 horsepower. Aftermarket turbo kits will give the single biggest boost to horsepower. Superchargers give a similar boost but use a different technology. While turbochargers recycle engine exhaust to spin the turbines and boost power, superchargers use the belt to force air into the engine. A turbo will give a bigger high-end boost, but a supercharger will burn cooler and deliver the power boost without the lag often associated with turbos.

    • 2

      Install an anti-ratchet sprocket to the track. A tight track will cause loss of horsepower. Loose tracks can lead to 'skipping,' a sporadic and momentary loss of traction. Anti-ratchet sprockets allow you to loosen the tracks, thus preserving horsepower, while eliminating skipping. Big wheel kits are often combined with an anti-ratchet sprocket to further reduce the resistance when the track is rolling, but this raises the center of gravity of the snowmobile, making it more prone to tipping over.

    • 3

      Use high performance lubricants and oils. You can boost the power of your engine with no modifications through the use of racing oils, filters and spark plugs. These products are more expensive than their standard counterparts and require more frequent changing, but they will improve performance without requiring any modifications to your engine or powertrain.

    • 4

      Consult your dealer before installing any big-bore kits, high-performance cylinder heads, or exhaust modifications to make sure they do not void any warranties you may have on the engine. If you are a mechanic, you can make these modifications yourself. If not, most small-engine shops can do them for you.