---
title: "Vertical Shaft Engine — $141K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/patio-lawn-garden/vertical-shaft-engine"
last_updated: "2026-08-05T23:22:53.910Z"
locale: en
meta:
description: "Niche score 49/100 · $141K/yr market · 232K searches/yr · $760.42 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 49/100 · $141K/yr market · 232K searches/yr · $760.42 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Vertical Shaft Engine — $141K/yr Amazon US Niche (2026) - Flapen"
---
# **vertical shaft engine**
**Skip it**
Pricing outside the sweet spot ($760.42 avg) — this niche doesn't clear our bar today.
Market size 31Growth 79Conversion 1Competition 68Returns 100Price range 0Avg price 0Brand share 2Review moat 93Quality gap 77
**Returns**
**Incredible****0.1%**
return rate — above 5% kills the launch gate
**Review moat**
**Great****148.07**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Great****+70.3%**
90-day search growth — must beat 0% to launch
**Quality gap**
**Great****4.3★**
avg incumbent rating — lower means beatable quality
**Competition**
**Good****44%**
top-5 click share — leaders hold, buyers still browse
**Market size**
**Okay****$141K**
$141K/yr · 232K searches
**Brand share**
**Bad****99%**
top-5 brand share — brand-locked demand
**Conversion**
**Bad****0.1%**
search→purchase rate — share of searches ending in a sale
**Avg price**
**Bad****$760.42**
avg listing price — sweet spot $15–$100
**Price range**
**Bad****$137.71–$3119.37**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Signals**[** High Price**](https://flapen.com/research/niches?market=us&signal=high_price "Avg price > $50")
According to Flapen's Amazon United States niche tracking, vertical shaft engine is a $141K/yr Amazon United States market (232K searches/yr). The top 5 brands hold 99% of demand. Demand peaks in Apr–May–Jun–Jul. Verdict: Skip it — 49/100.
Data updated Jul 9, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **vertical shaft engine market data**
- **Units sold / yr**
- **250–500**
- avg 0–100/product
- **Revenue / yr**
- **$190K–$380K**
- units × avg price
- **Conversion rate**
- **0.1%**
- **Avg BSR**
- **#2,914**
- **Page quality**
- **0%**
- **Prime**
- **17%**
- **Sponsored**
- **73%**
- **Out of stock**
- **7.4%**
- **Avg brand age**
- **35 months**
- **Avg seller age**
- **174 days**
## **Competition & brand share**
The top 5 products take 44% of clicks — established leaders, but buyers still shop beyond them.
**Brands**
**6 **▼falling
**Sellers**
**28**
**Top-5 brand share**
**99%**
Top 20: 100%
**Top-5 click share**
**44%**
Top 20: 90%
**Open market**
**0%**
- Briggs & Stratton76% - Aceup Energy18% - Generic2% - Kawasaki2% - BILT HARD2% - LUPENGSHOP1%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +70.3% search growth over the last 90 days.
6K4KSpike '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Apr, May, Jun, Jul · busiest ÷ quietest = 2.7×
[**Open Trend **](https://flapen.com/research/us/patio-lawn-garden/vertical-shaft-engine/trend)
## **Top vertical shaft engine search terms**
- **vertical shaft engine**42K/yr+87.8%0.1% conv. - **lawn mower engine**26K/yr+81.0%0.2% conv. - **briggs and stratton engine**27K/yr+57.7%0.2% conv. - **briggs stratton replacement engines**21K/yr+80.2%0.1% conv. - **vertical engine**12K/yr+91.8%0.1% conv. - **vertical shaft gas engine**11K/yr+26.4%0.2% conv. - **lawn mower motor**9K/yr+110.1%0.1% conv. - **mower engine**10K/yr+62.9%0.1% conv. - **replacement lawn mower engine**7K/yr+69.7%0.1% conv. - **vertical shaft lawn mower engine**9K/yr+167.3%0.4% conv. [**All search terms **](https://flapen.com/research/us/patio-lawn-garden/vertical-shaft-engine/search-terms)
## **Top vertical shaft engine products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%3%$4K6%$8K9%$13K12%$17K1101001K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)1 product missing review or click data not plotted
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Briggs and Stratton Vertical 17.5 HP 500cc INTEK Engine 9amp 1 x 3-5/32 #31R977-0054**Briggs & Stratton**$716.32**4.6★354 rev](https://www.amazon.com/dp/B07F261TPJ) [2**Briggs & Stratton 14D932-0110-F1 Professional Series 10 GT 223cc Vertical Engine**Briggs & Stratton**$317.16**4.2★8 rev](https://www.amazon.com/dp/B0CCXG822P) [3**Aceup Energy Gas Engine Vertical Shaft 4.4HP 173cc 4-Stroke OHV Gas Motor with Primer for Lawn Mower EPA Compliant**Aceup Energy**$142.53**4.1★115 rev](https://www.amazon.com/dp/B0D48ZW86X) [4**Briggs & Stratton 104M02-0197 7.25tp 163cc Vertical Shaft 7/8 x 3-5/32 Inch for mowers**Briggs & Stratton**$240.76**4.2★43 rev](https://www.amazon.com/dp/B0BYWDNCV7) [5**Briggs & Stratton 44S977-0032-G1 25 GHP Vertical Shaft Engine Black**Briggs & Stratton**$1155.23**4.5★100 rev](https://www.amazon.com/dp/B07B8WV67P)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Aceup Energy 4.4HP 173cc 4-Stroke Gas Motor Gas Engine Vertical Shaft with Primer for Lawn Mower**Aceup Energy**$137.71**14 rev4mo ago](https://www.amazon.com/dp/B0GQ9J1FPM) [**Aceup Energy 4.4HP 173cc Gas Engine Vertical Shaft 4-Stroke Gas Motor with Primer for Lawn Mower**Aceup Energy**$138.36**14 rev12mo ago](https://www.amazon.com/dp/B0FHH2NF68) [**Briggs & Stratton 49T877-0049-Z1 Commercial Series 27 HP 810cc Vertical Engine**Briggs & Stratton**$1418.70**0 rev1y ago](https://www.amazon.com/dp/B0F8MYD69B) [**Briggs & Stratton 93J02-0001-F1 Ex Series 6.25 GT 150cc Vertical Shaft Engine**Briggs & Stratton**$290.25**1 rev1y ago](https://www.amazon.com/dp/B0F8MXFYJ7) [**24 HP 724cc Intek Series Engine 1 x 3-5/32 inch (Replaces Briggs 44N877)**Generic**$1192.11**8 rev1y ago](https://www.amazon.com/dp/B0F83CHTVN)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Aceup Energy 4.4HP 173cc 4-Stroke Gas Motor Gas Engine Vertical Shaft with Primer for Lawn Mower**Aceup Energy**$137.71**4.4★**▲ 193%**](https://www.amazon.com/dp/B0GQ9J1FPM) [**Briggs & Stratton 40N777-0027 20hp 656cc Intek Series 1 x 3-5/32 9 Amp**Briggs & Stratton**$890.32**4.7★**▲ 190%**](https://www.amazon.com/dp/B0BTWL52R6) [**Briggs & Stratton 14D932-0110-F1 Professional Series 10 GT 223cc Vertical Engine**Briggs & Stratton**$317.16**4.2★**▲ 140%**](https://www.amazon.com/dp/B0CCXG822P) [**Briggs & Stratton 93J02-0001-F1 Ex Series 6.25 GT 150cc Vertical Shaft Engine**Briggs & Stratton**$290.25**5.0★**▲ 140%**](https://www.amazon.com/dp/B0F8MXFYJ7) [**Briggs & Stratton 49T877-0049-Z1 Commercial Series 27 HP 810cc Vertical Engine**Briggs & Stratton**$1418.70**0.0★**▲ 83%**](https://www.amazon.com/dp/B0F8MYD69B)
**~~View all trending →~~**
## **What buyers say about vertical shaft engine**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**21%
*“Perfect fit”*
**Motor Power**20%
*“Good motor”*
**Value For Money**15%
*“Good value”*
**Assembly/Installation**11%
*“fairly easy to install”*
**Quality-Overall**9%
*“Great product”*
**Advertised Vs Actual Product**3%
*“Better than expected”*
**Ease Of Use**3%
*“Easy, easy”*
**Socket/Port/Plug**3%
*“Easy swap plug and play”*
**Strength**3%
*“its very strong”*
**Safety Standards**1%
*“Safety”*
### **What buyers complain about **
**Durability**28%
*“which means it won't last long”*
**Quality-Overall**19%
*“Government intrusion causing quality issues”*
**Motor Issues**11%
*“Engine not plug”*
**Functionality-Overall**4%
*“Engine did not work”*
**Ease Of Use**4%
*“Not as easy as it looks”*
**Size-Overall**4%
*“1 - the carburetor bowl is very shallow”*
**Instructions/User Manual/Troubleshooting**3%
*“Great Engine, poor instructions”*
**Advertised Vs Actual Product**2%
*“How ever engine sent was'nt as represented in online presentation”*
**Value For Money**2%
*“Not a good deal”*
**Add-Ons/Attachments**2%
*“Not worth the hassle to add them”*
### **Top return reasons **
**Size-Overall**74%
**Defective Material/Parts**9%
**Motor Issues**5%
**Advertised Vs Actual Product**5%
**Strength**2%
**Value For Money**2%
**Add-Ons/Attachments**1%
**Mechanism Issues**1%
## **Common questions**
- **Is vertical shaft engine profitable to sell on Amazon United States?**
- The niche generates $141K/yr across 30 tracked products. 1 of 2 products launched in the last 360 days are still selling. 90-day search growth is +70.3%. Flapen's verdict: Skip it (49/100).
- **How competitive is the vertical shaft engine niche?**
- 6 brands and 28 sellers compete. The top 5 products take 44% of clicks and top 5 brands hold 99% of demand.
- **What do buyers complain about in vertical shaft engine?**
- Top complaints mined from reviews: Durability, Quality-Overall, Motor Issues. The return rate is 0.1%.
- **When does demand for vertical shaft engine peak?**
- Demand peaks in Apr–May–Jun–Jul; the busiest month runs 2.7× the quietest.
- **What does it cost to enter the vertical shaft engine niche?**
- Listings span $137.71–$3119.37; the average listing price is $760.42 (sweet spot $15–$100). The average incumbent carries 148 reviews — the moat a new listing must climb.
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