Marcy Folding Motorized Treadmill JX-663SW

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Marcy JX-663SW

Check Discounted Price
245 lbs2.5 HP,
0.5-9.0 MPH
10 programs,
3 user
2 years

The Marcy JX-663SW treadmill offers a bit more than the JX-650W model, but still is an entry-level machine, made for walking and jogging, and not running at full speeds. As opposed to the JX-650W, this treadmill has motorized incline, a slightly more powerful motor, and a little larger running surface.

Technical Details and Specifications

  • Assembled dimensions: 67L x 30W x 53H inches (170L x 76W x 135H cm)
  • Tread belt dimensions: 50L x 17.7W inches (127 x 45 cm)
  • Assembled weight: 145 lbs (65.7 kg)
  • Supported weight: 245 lbs (111 kg)
  • Motor: 2.5 HP
  • Incline: Motorized, 0%-15%
  • Speed range: 0.5 – 9.0 MPH
  • Console: 10 pre-set workouts, 3 user settings, 1 manual mode
  • Extras: Speakers, accessory holders, tablet holder
  • Warranty: 2 years limited

Frame and deck

The Marcy JX-663SW treadmill features a cushioned deck, which integrates a set of two dampers at the middle of the deck on each side, similar to the NordicTrack T 6.5S and ProForm Power 995i. These not only reduce some of the impact on your joints during your workout, they also reduce some of the cadence noise. 

The deck is rated for a user weight of 245 lbs (111 kg), which is not bad for a machine in this feature and price range. The belt offers a running surface of 50″L x 17.7″W (127 x 45 cm), a bit longer and wider than for the JX-650W model. However, it’s still a running surface intended for walking and jogging, and not running at high speeds. Therefore, users who are taller than 6’0″ (183 cm) may step on the motor cover if they engage in running workouts at the top speeds of the machine. But nonetheless, the treadmill does offer the possibility to run at speeds up to 9.0 MPH. We’ll cover this aspect in more detail in one of the sections below.

Although it’s not a large fitness machine, the Marcy JX-663SW treadmill still takes quite a bit of space when fully assembled and unfolded. Its footprint is approx. 67″L x 30″W (170 x 76 cm), to which you should add at least three feet of clearance at the rear and at least two feet of clearance on the sides for safe operation. But on the other hand, the machine’s deck is foldable. By folding it up, the treadmill’s length is reduced by more than half. The folding mechanism integrates a hydraulic cylinder, so its unfolding is assisted, to prevent damage.

Even though it’s not a gym-grade treadmill, the Marcy JX-663SW still is pretty heavy. When fully assembled, it weighs approx. 145 lbs (65.7 kg), so it’s recommended to be transported and assembled by two people. However, once it is fully assembled, its relocation isn’t too difficult as its base integrates transport wheels.

Last but not least, this Marcy treadmill features a steel frame, double-coated with a corrosion-resistant powder finish. The only color available is gray.

Incline & step-up height

This Marcy treadmill is equipped with a motorized incline system, which consists in a small motor and a small lift situated at the front of the deck. Since the incline is motorized, it can only be adjusted from the console. As you adjust the incline, the lift will slowly elevate the deck at the front.

The machine offers an incline range between 0% and 15%. The increments available are 1%. There are gradual incline keys both on the console and integrated into the left handlebar. However, the console also features quick adjustment keys for the 2,8,12 and 15 incline settings.

Evidently, since the incline system is motorized, some of the built-in programs will auto-adjust the incline of the deck, depending on the segment of the workout.

One last aspect to mention here regards the deck’s step-up height. When unfolded and in the usage position, the deck’s running surface stands approx. 9″ (23 cm) above floor level. This being said, it is recommended to place and use the machine in a room with a ceiling taller than your own height by at least 16″-17″ (40-43 cm), in order to avoid any issues.


As we’ve mentioned above, the motor on the Marcy JX-663SW treadmill is a bit superior to the one on the JX-650W model. It has a continuous power of 1.25 CHP and a peak power of 2.5 HP. Differently put, even if you’re close to the 245 lbs (111 kg) weight capacity of the machine, you should still be able to run at speeds of 7-8 MPH, for at least 10-15 miles, without the motor to overheat or lose performance.

The belt’s starting speed point is 0.5 MPH, but up from this, you can adjust the speed in increments of 0.1 MPH. This is a plus, as you can easily find the most suitable pace for your workout.

Just as for the incline, there are keys for gradual speed adjustment on the console and incorporated in the right handlebar. There are also keys for quick speed adjustment, for the 2,4,6, and 8 MPH speed settings.

Last but not least, since it’s a basic motor, its power consumption is also minimal. In other words, even if you will be using it daily, it shouldn’t add more than a few dollars to the electricity bill.


This Marcy treadmill is equipped with a mid-range, programmable console. It has a 5″ LCD display with blue backlight, which tracks time, distance, calories, and pulse. Speed and incline are also shown. 

The console is not telemetric. It cannot track your pulse via a wireless HR chest strap transmitter. Therefore, in order to monitor your pulse, you will have to use the stainless steel sensors integrated into the handlebars.

The console unit doesn’t have any online capabilities. However, it has 10 preset programs which automatically adjust the speed and the incline. These programs cover standard workouts, such as intervals, weight loss, peak, ascension etc. On top of that, there are 3 user settings which give you the possibility to create and save your own 3 custom programs. And finally, there’s also the manual mode which allows you to adjust the speed and incline as you like during your workout.

In terms of amenities, there are three main elements to mention here. These are the integrated sound system, the side trays, and the tablet holder. The side trays are large enough to accommodate various accessories, such as phone, water bottle, keys, earplugs, TV remote control, etc.

The tablet holder it placed right above the console controls. The space assigned to the tablet is fairly large, so a tablet placed here won’t cover the treadmill’s display.

The sound system is compatible with most smartphones or MP3 players. It consists of two speakers which render a sound quality that is considerably better than the speakers of a smartphone. The jack is placed on the right side of the LCD display of the console and a cable adapter for is supplied with the machine.

Assembly and Maintenance

The assembly of this treadmill doesn’t require much. The deck with the motors, belt, rollers and the other parts, comes pre-assembled. So, in terms of assembly, you only have to attach the upright console masts and the console. This shouldn’t take longer than 30 min. The manual offers excellent assembly instructions, while the tools required for it are included.

Maintenance requires keeping the belt clean in order to prevent any textile fibers or small objects to be dragged into the motor. The deck comes pre-lubricated; however, just as any other treadmill, it will require periodic lubrication.

The Pros

  • Sturdy construction, capable of supporting users up to 245 lbs;
  • Small footprint compared to other treadmills;
  • Folding deck, space-saving design;
  • Adjustable stabilizers;
  • Transport wheels;
  • Two shock absorption elements on each side of the deck;
  • Motorized incline with a range between 0-15%;
  • Speed settings up to 9.0 MPH;
  • Speed adjustment increments of 0.1 MPH, giving you the possibility to find the perfect pace for your workout;
  • Speed and incline controls built-in the handlebars;
  • EGK pulse sensors built-in the handlebars;
  • Low power consumption; 
  • LED backlit display;
  • 10 pre-set workout programs;
  • 3 goal settings for time, distance, and calories;
  • Accessory trays built-in the dashboard;
  • Sound system included;
  • Tablet holder included;
  • Very easy to assemble;
  • Little maintenance required.

The Cons

  • Rather short running surface;
  • No cooling fan.


The Marcy JX-663SW is an entry-level treadmill for walking and jogging, equipped with a 2.5 HP peak power motor, motorized incline, and a console with 10 preset programs. Its incline and speed range between 0%-15% and 0.5-9.0 MPH. Its frame has a folding design and weight capacity of 245 lbs (111 kg). It’s an excellent treadmill for muscle toning, light to mid-range cardio, endurance training and weight loss. And finally, it’s not an expensive fitness machine, offering excellent value for the price.

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