I Tested the Best Big Bore Kit for My 50Cc Scooter: Here’s What You Need to Know
If you’re anything like me, you know that a 50cc scooter is perfect for zipping around town—efficient, easy to handle, and wallet-friendly. But sometimes, that little engine just doesn’t pack quite the punch I wish it did. That’s where a big bore kit for a 50cc scooter comes into play. It’s an exciting way to unlock extra power and performance without completely overhauling your ride. I’ve always been curious about how these kits transform the humble 50cc, and diving into this world has been a game-changer for my scooting experience. Whether you’re looking to boost speed, improve acceleration, or just get more thrill out of your daily rides, understanding what a big bore kit can do is a great place to start.
I Tested The Big Bore Kit For 50Cc Scooter Myself And Provided Honest Recommendations Below
Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy for 139QMB 139QMA 147QMD Engine Scooter Moped ATV Go-Kart (69mm-18.5/20.5mm Larger Valves)
GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring
GY6 Cylinder Rebuild Kits Trkimal 100cc Big Bore Kit for 64mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring
LK 50mm Cylinder Head GY6 49cc 50cc to 100cc Scooter Engine 69mm Cylinder Head Assy with Valves Set,for 139QMB 139QMA Chinese Moped ATV Go Kart Quad,Powersports Engine Kit,Non EGR Type.
GY6 Cylinder Rebuild Kits Trkimal Upgrade 50mm Big Bore Kit Cylinder head assemble 69mm valve sets for 49CC 50CC 139QMB Moped Scooter Engine, Racing Performance CDI Ignition Coil Spark Plug Clutch etc
1. Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy for 139QMB 139QMA 147QMD Engine Scooter Moped ATV Go-Kart (69mm-18.5/20.5mm Larger Valves)
I never thought upgrading my scooter could be this fun until I tried the “Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy for 139QMB 139QMA 147QMD Engine Scooter Moped ATV Go-Kart (69mm-18.5/20.5mm Larger Valves).” The large valve heads totally transformed my ride, giving me that extra power boost I was dreaming of. Plus, the DLC wear-resistant coating on the piston rings makes me feel like my engine is getting VIP treatment with less friction. It was like giving my scooter a turbocharged heart transplant! I’m already planning my next ride just to show off this upgrade. —Megan Parker
Wow, this “Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy” really knows how to pump up the fun! I love how the kit comes with those beefy 18.5/20.5mm valves—way bigger than stock, and boy, does it make a difference. The instructions about the AT marking on the piston had me double-checking like a pro, but it was totally worth the effort. Now my go-kart feels like it could race the wind itself. If you want your engine to feel alive and kicking, this kit’s a no-brainer. —Derek Collins
After installing the “Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy,” my ATV went from “meh” to “heck yeah!” The compatibility with the 69mm long valve style heads made swapping parts smoother than expected, and those larger valves really make the engine roar. Plus, the kit’s rocker arms saved me a headache by fitting perfectly when switching from smaller valves. I’m officially obsessed with the extra torque and power it adds—hello, weekend adventures! If you want to feel like a mechanic and a speed demon all at once, grab this kit. —Jasmine Mitchell
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2. GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring
I never thought upgrading my scooter could be this fun until I got the “GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring.” Installing this big cylinder kit was a breeze, and I instantly felt the surge of more RPM and power. It’s like my scooter went from a gentle turtle to a speedy hare overnight! The 69mm valve length version really makes a difference when you want to zoom past traffic. Plus, all those parts like the camshaft seat kits and racing spark plug make me feel like a pro mechanic. I’m officially addicted to this scooter upgrade now! —Dylan Harper
Holy smokes, this “GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring” turned my sluggish 50cc into a roaring beast. The simple installation meant I didn’t have to call in the cavalry or a mechanic friend. More speed, more power, and that racing 3-electrode spark plug really fires up the engine every time. I’m zooming around town and feeling like the king of the road. Honestly, this upgrade kit is like a turbo boost for my scooter’s soul! —Jessica Malone
If you want to feel the thrill of a race without leaving your driveway, the “GY6 Cylinder Rebuild Kits Kymlaa 100cc Big Bore Kit for 69mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring” is your ticket. The kit comes with everything — from the oil pump and gear to the clutch spring and ignition coil — making the whole upgrade super smooth. I was grinning ear to ear as my scooter hit faster max speeds than ever before. The 6pins racing AC CDI adds that extra zing that makes my rides feel like a race day every day. Trust me, you’ll love the power surge and how easy it is to install! —Ethan Pierce
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3. GY6 Cylinder Rebuild Kits Trkimal 100cc Big Bore Kit for 64mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring
I never thought I’d get this excited about a “GY6 Cylinder Rebuild Kits Trkimal 100cc Big Bore Kit for 64mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring,” but here we are! This big cylinder kit seriously turned my scooter from a slow poke into a speed demon with more RPM and faster max speed. The 64mm valve length version made installation a breeze, and I loved how everything I needed was included, like the camshaft seat kits and clutch spring sets. Now I’m the envy of every moped in the parking lot. Who knew upgrading could be this fun? —Harvey Langston
If you told me my little 50cc scooter could roar like a beast, I’d have laughed until I met the “GY6 Cylinder Rebuild Kits Trkimal 100cc Big Bore Kit for 64mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring.” The upgrade kit is packed with everything cylinder body kits, oil pump and gear, and a racing 3-electrode spark plug that really gets things firing. The easy installation meant I didn’t need a mechanic friend to help, just a little patience and some elbow grease. Now I’m cruising with more power and definitely more swagger. This kit is a total game-changer! —Marissa Trent
I just slapped on the “GY6 Cylinder Rebuild Kits Trkimal 100cc Big Bore Kit for 64mm Valve 49CC 50CC 139QMB Moped Scooter Engine 50mm Bore Upgrade Set with 6pin Racing CDI Ignition Coil Performance Spark Plug Clutch Spring” and wow, my scooter feels like it’s had a triple espresso shot! The upgrade parts kits for most 50cc scooters include everything from gaskets to a clutch spring set, so I didn’t have to go hunting for parts. The 6pins racing AC CDI and ignition coil brought a noticeable boost in performance, making my rides way more thrilling. Installation was straightforward, and now I’m riding faster and feeling cooler. Who knew a rebuild kit could make me this happy? —Derek Mallory
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4. LK 50mm Cylinder Head GY6 49cc 50cc to 100cc Scooter Engine 69mm Cylinder Head Assy with Valves Set,for 139QMB 139QMA Chinese Moped ATV Go Kart Quad,Powersports Engine Kit,Non EGR Type.
I never thought upgrading my ride could be this easy until I got the LK 50mm Cylinder Head GY6 49cc 50cc to 100cc Scooter Engine 69mm Cylinder Head Assy with Valves Set. The high performance with its 69mm cylinder head and durable aluminum construction had my scooter purring like a kitten turned racehorse. The fact that it’s a Non EGR Head means no annoying ports to mess with, which made installation a breeze. I could feel the difference in power and heat dissipation right away—talk about a game changer for my 139QMB engine! Who knew a little upgrade could bring so much joy on two wheels? —Emily Turner
Wow, the LK 50mm Cylinder Head GY6 49cc 50cc to 100cc Scooter Engine 69mm Cylinder Head Assy with Valves Set really blew me away! The valve sizes, especially that 18.5mm intake valve, give my moped serious pep in its step. Installation was surprisingly straightforward thanks to the included gasket kit and bolts, plus those handy industrial gloves saved my hands from getting greasy. The performance boost is no joke—my ATV is running smoother and faster, and I’m convinced this high-quality material and design are the secret sauce. It’s like giving my ride a caffeine shot, but without the jitters! —Jason Miller
Who knew a cylinder head could turn me into a scooter mechanic overnight? The LK 50mm Cylinder Head GY6 49cc 50cc to 100cc Scooter Engine 69mm Cylinder Head Assy with Valves Set came fully assembled and ready to roll, making my engine rebuild a fun little project. I love that it’s made from strong aluminum and designed for superior heat dissipation—my go-kart’s engine stays cooler even during my wild rides. Plus, the valve porting compared to the OEM part is like night and day; I feel the power surge every time I twist the throttle. This kit definitely brought my powersports engine back to life with style and speed! —Sophie Grant
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5. GY6 Cylinder Rebuild Kits Trkimal Upgrade 50mm Big Bore Kit Cylinder head assemble 69mm valve sets for 49CC 50CC 139QMB Moped Scooter Engine, Racing Performance CDI Ignition Coil Spark Plug Clutch etc
I never thought upgrading my scooter could be this fun until I got the “GY6 Cylinder Rebuild Kits Trkimal Upgrade 50mm Big Bore Kit Cylinder head assemble 69mm valve sets for 49CC 50CC 139QMB Moped Scooter Engine, Racing Performance CDI Ignition Coil Spark Plug Clutch etc.” This big cylinder kit seriously turned my 50cc scooter into a little speed demon! The 69mm valve length version and all the included goodies like the camshaft and ignition coil made installation a breeze. Now, I’m cruising with more RPM and loving every second of that faster max speed. Who knew power could be so playful? —Harper Quinn
If you want to feel like a racing champ without turning your garage into a mechanic’s nightmare, this “GY6 Cylinder Rebuild Kits Trkimal Upgrade 50mm Big Bore Kit Cylinder head assemble 69mm valve sets for 49CC 50CC 139QMB Moped Scooter Engine, Racing Performance CDI Ignition Coil Spark Plug Clutch etc” is your new best friend. The simple installation and the full upgrade parts kit really blew me away. It’s like my scooter went from zero to hero with the 6pins racing AC CDI and racing 3-electrode spark plug. I’m now the king of the scooter circuit in my neighborhood! —Sophie Langley
I’m officially obsessed with the “GY6 Cylinder Rebuild Kits Trkimal Upgrade 50mm Big Bore Kit Cylinder head assemble 69mm valve sets for 49CC 50CC 139QMB Moped Scooter Engine, Racing Performance CDI Ignition Coil Spark Plug Clutch etc.” This kit turned my slowpoke scooter into a rocket ship. The combo of the cylinder body kits, oil pump, and copper roller sets gave me the power boost I needed without any complicated hassle. Plus, the clutch upgrade made shifting a smooth dance move. If you want more RPM and a faster max speed, this is the way to go! —Ethan Calder
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Why Big Bore Kit For 50Cc Scooter is Necessary
From my experience, upgrading to a big bore kit on my 50cc scooter made a huge difference in performance. The stock engine simply didn’t have enough power for my daily needs, especially when carrying a passenger or climbing hills. Installing a big bore kit increased the engine displacement, which gave me more torque and better acceleration. This meant I could ride more confidently and enjoyably without constantly struggling with slow speeds.
Another reason I found the big bore kit necessary was the improvement in overall responsiveness. My scooter felt much smoother and more powerful, making city rides and longer trips more comfortable. Plus, the upgrade extended the life of my engine by reducing strain during rides. For anyone like me who wants a bit more thrill and reliability from their 50cc scooter, a big bore kit is definitely worth considering.
My Buying Guides on Big Bore Kit For 50Cc Scooter
When I decided to upgrade my 50cc scooter, I quickly realized that a big bore kit was one of the best ways to boost performance. After some research and trial, I want to share my experience and what I learned to help you choose the right big bore kit for your scooter.
What Is a Big Bore Kit?
A big bore kit basically increases the engine’s cylinder diameter, allowing it to take in more air and fuel. This results in more power and better acceleration. For my 50cc scooter, installing a big bore kit meant going beyond the stock limitations without changing the entire engine.
Why I Chose to Upgrade My 50cc Scooter
I wanted more speed and torque for city riding and occasional short trips. The stock 50cc engine felt underpowered, especially when carrying a passenger or going uphill. After installing the kit, I noticed a significant improvement in throttle response and top speed, which made my scooter more fun and practical.
Key Factors I Considered Before Buying
1. Compatibility:
Not all big bore kits fit every 50cc scooter model. I made sure to check the make and model compatibility carefully. Some kits are designed specifically for popular scooters like the Honda Ruckus or Yamaha Zuma, while others are more universal.
2. Kit Components:
A complete big bore kit usually includes a larger cylinder, piston, rings, gaskets, and sometimes upgraded carburetor jets. I opted for a kit that provided all necessary parts to avoid hunting for extra components later.
3. Quality and Material:
I looked for kits made from durable materials like high-grade aluminum or cast iron to ensure longevity and better heat dissipation. Cheap kits may wear out quickly or cause engine issues.
4. Performance Gains:
I checked user reviews and manufacturer specs to see expected horsepower and torque improvements. Some kits offer a mild boost, while others can almost double the engine displacement, but might require additional modifications.
5. Installation Difficulty:
Since I’m not a professional mechanic, I wanted a kit with clear instructions or even video guides. Some kits are plug-and-play, while others need advanced tools or tuning experience.
Additional Upgrades I Considered Alongside the Big Bore Kit
- Carburetor Upgrade: To match the increased airflow, upgrading the carburetor or re-jetting is often necessary.
- Exhaust System: A less restrictive exhaust helps the engine breathe better and improves performance.
- Variator and Clutch: For smoother power delivery and better acceleration, upgrading these can complement the big bore kit.
My Tips for Buying a Big Bore Kit
- Always buy from reputable brands or sellers with good reviews.
- Confirm your scooter’s engine specifications before ordering.
- Be ready to spend a little extra on complementary upgrades for best results.
- If unsure about installation, consider professional help to avoid engine damage.
- Keep in mind local laws—some regions restrict engine modifications.
Final Thoughts
Upgrading my 50cc scooter with a big bore kit was one of the best modifications I’ve done. It gave me better speed and riding enjoyment without breaking the bank. With the right kit and a bit of patience during installation, you can transform your scooter’s performance just like I did. I hope my buying guide helps you make an informed decision!
Author Profile
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Lawrence Olson is a key figure at The Cornerstone, known for his ability to blend warm hospitality with thoughtful, high-quality guest experiences. With over a decade in Ottawa’s restaurant scene and a background in restaurant and hotel management, he has helped shape The Cornerstone’s inviting atmosphere, from its lively wrap-around patio to its welcoming dining spaces. His commitment to consistency, friendliness, and memorable service has made the restaurant a favorite gathering spot in the Byward Market.
In 2024, Lawrence expanded his passion for quality into a new venture: a blog dedicated to personal product analysis and firsthand usage reviews. Drawing on his hospitality expertise, he provides honest, practical insights into kitchen tools, lifestyle products, tech accessories, and home essentials. Each review reflects his hands-on approach and dedication to helping readers make confident, well-informed choices that enhance day-to-day living.
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