Briggs and Stratton Vertical 17.5 HP 500cc INTEK Engine 9amp 1" x 3-5/32" #31R977-0054
Condition: New
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Availability:
In Stock.
Arrives
Saturday, Jul 25
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Features
- Cast iron cylinder sleeve and dual element air filter for extended engine life
- Patented linear balancing system provides smoother performance
- 9 amp/electric start only
- 1" x 3-5/32" shaft, tapped 7/16" with 1/4" keyway
- Common riding mower replacement engine
Description
This genuine 500cc Briggs & Stratton single cylinder engine offers dependable power for your equipment needs. With a power rating of 17.5 horsepower, this engine features a premium Dual Clean air filtration system, electric starter, and maintenance-free Magnetron electronic ignition. With a manufacturer limited warranty of 2 years consumer use / 1 year commercial use, Briggs & Stratton provides power that you can trust. This engine includes a Dura-Bore cast iron cylinder sleeve for extended life. This engine includes a fuel pump. This engine includes an oil filter. This engine includes a 9 amp charging system.
Product Dimensions: 19 x 4 x 4 inches
Item Weight: 79.2 pounds
Manufacturer: Briggs and Stratton
Is Discontinued By Manufacturer: No
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Saturday, Jul 25
This item is non-returnable:
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
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Top Amazon Reviews
Replaced 16hp engine in Toro Timecutter 1642z. The electrical connectors were a direct connection with no splicing required. Plug and play. Everything was very easy to swap. Fired up instantly. Starts with just a click every time.
Reviewed in the United States on May 9, 2026 by Lannie
I needed to replace the 16.5 HP B&S motor on my DR ProXL30 brush mower, because the decompression mechanism no long worked and the starter could not overcome the compression. This 17.5 HP B&S motor is a perfect replacement. It comes with starter, electric fuel solenoid, alternator, and magneto, but it does not come with a muffler. Before disposing of the old motor, be sure to save the 3 self-tapping mounting bolts, the connectors from the old motor and the muffler parts. The motor comes with no instructions on mounting or wiring, but it is pretty straight forward. The 3 mounting bolts are self-tapping in the new aluminum motor frame; you do not need to tap the holes. The pulleys and electric clutch are held in place by a single shaft bolt and Woodruff keys, These are easily removed from old motor and fit perfectly on the shaft of the new motor. The new motor comes with 3 wires to be connected to the existing wire harness on the mower - a red for the alternator, gray for the fuel solenoid and black wire for the magneto - but it requires repurposing 3 old connectors (round single pin, flat 2 pin and square 6 pin connector). Basically you connect the gray to the gray, black to the black and red to red using the old connectors (ignore the orange wire) aided by wire quick-connects or wire nuts. After being fueled, the motor started immediately when ignition key was turned. I couldn't be happier with the new motor, but let us hope these new motors will not have the decompression starting problems that plagued the original motors.
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Reviewed in the United States on October 4, 2024 Reviewed in the United States on October 4, 2024 by Ancient Mariner
Came complete except exhaust bolts. New mounting bolts would have been nice too. I used grade 8 - 5/16” bolts and locking washers and nuts. Installed on a 1998 Craftsman LT1000. Wiring was simple enough, pigtail for carb was easily spliced and the red hot wire on the ignition module went to the red hot on the mower. Fired right up. Made the mower like new again, plenty of power and less vibration. Hopefully it lasts a long time. I know BS has the fragile cam issue, which is why I bought this replacement. I can repair my old I/C easily enough and will put it on the shelf for a spare. This is a great value for the money.
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Reviewed in the United States on October 24, 2025 by Charles Henderson
surprised it fit perfectly with the original mount. the throttle cable and solenoid plus ignition works perfectly. had to splice 2 wires but other than that everything matched including bolts, spacers, key stock, washers and drive pulley beside the muffler but I knew that when I bought it. Original mower I bought 20 years ago but the new motor so far running great mowing 4 acers
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Reviewed in the United States on May 20, 2026 by Amazon Customer
I am not a small engine mechanic. Circa 2 years ago, I replaced compression relief valve or cam in my Briggs & Stratton Intex 17.5 engine. Circa 7 months ago, its engine pushed an exhaust rod through its engine head. Cost of new riding mowers is higher than my used SUV so, May 2025, I purchased this engine at a cost of $750. It was professionally packaged, shipped & upon arrival, it easily passed my visual inspection. Installation was simple due to its exact replacement. However, it did not include wiring harness. After completing wiring harness & adding 20-50 oil, I attempted to start engine. No exaggeration, within 2 seconds, maybe less than 1, engine started and remained running in what appeared to be perfection. Due to new engines having metal shavings in them, after 50 minutes of cutting grass, I changed its oil filter. What was odd, it strongly appeared none of my 20-50 oil had circulated into its oil filter. After 3rd or 4th time cutting grass, my transmission became difficult to shift as my brakes failed, so in a rush, I over rev its engine, quc8kly realized my error and shut off engine. However, it failed to re-start. After extensive diagnosis, I decided to replace its new ignition coil with one from my exploded engine. Amazingly, engine started right up & ran like new. Just to be certain, I then replaced its new ignition coil back onto engine. It failed to start. I then went to our local Briggs & Stratton dealership (related) to obtain a new coil. However, manager refused to exchange it for a new coil. He suggested, I bring in my entire mower, where his staff would run their own diagnosis. Then they would report their findings to Briggs & Stratton who would then determine if I had a valid warranty claim, or they would sell me a new coil circa $47. Know this, Briggs & Stratton does not easily replace parts or uphold their warranty. Engine has continue to perform good to excellent. For its price, yes I would happily purchase another.
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Reviewed in the United States on September 8, 2025 by Pleased customer
Real good replacement engine for my 15 horsepower John Deere saber direct bolt on and basically plug and play easiest install I ever done took about an hour. Also it came in a very big box not damaged and very good how it was packed inside hats off to Briggs & Stratton and small engine company for where it came from
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Reviewed in the United States on May 7, 2026 by Bill
After 22 years the original 18hp B&S engine on my old Troy-bill lawn tractor seized up when the throttle came apart and the screws got sucked into the cylinder. The mower has been serviced and garage kept over the years and is in good shape otherwise, so I didn’t want to scrap it and buy a new mower. I decided to replace the engine with this one after reading the overly positive reviews and received shipment in two days. Even though most say you can get the mounting bolts to work without cutting threads in the mounting holes on the aluminum block, I tapped mine anyway. This engine fit perfectly with the only issue being the vacuum line behind the engine going to the fuel pump is wedged against the fuel tank, but works just fine. There is an extra wire (orange) from the original engine coming from the alternator that is not used in this new engine, otherwise all of the wires are the same color and function. I hooked them up to the old engine side wiring harness connector leaving the orange harness wire cut and capped off. Added oil to the engine, hooked up the gas line and it cranked right up. I’ve mowed twice with it so far and it is every bit as powerful as the original 18 hp engine was and runs smooth. I have a yard with some steep slopes and this engine does not even slow down going up steep grades. As I discovered later, the orange alternator wire on the old engine powered the mower headlights. But I pulled power from the single alternator wire to the light circuit at the ignition switch and the headlights are working again. Time will tell if this engine will be as good as the old one, but for now I feel good about this purchase.
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Reviewed in the United States on May 5, 2025 by J. Baxter
This Revived my 12 year old D105 mower. Would highly recommend
Reviewed in the United States on April 24, 2026 Reviewed in the United States on April 24, 2026 by GC