I Tested the 50Cc Big Bore Kit: Here’s What You Need to Know Before Upgrading
When I first heard about the 50Cc Big Bore Kit, I was instantly intrigued by the promise of transforming a modest 50cc engine into something far more powerful and exciting. For anyone who’s ever felt limited by the standard performance of their small engine, the idea of unlocking hidden potential is incredibly appealing. This little upgrade has quickly become a game-changer for riders looking to boost speed, torque, and overall ride quality without investing in a completely new bike. Whether you’re a casual rider or a seasoned enthusiast, the 50Cc Big Bore Kit offers a fascinating glimpse into what’s possible with a bit of mechanical know-how and the right parts.
I Tested The 50Cc Big Bore Kit 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)
Glixal ATMT1-011 139QMB 139QMA Scooter Big Bore Cylinder Kit Rebuild Kit GY6 100cc 50mm Moped ATV Go-Kart
CLEO GY6 50cc-100cc Cylinder Head Kit Assy 50mm Big Bore with 69mm Valves for 139QMA 139QMB Engine Scooter Moped ATV Go Kart Quad
ZTDZZH 50mm Bore Cylinder Head Kit for GY6 50cc to 100cc Engine with 69mm Valves scooter taotao kazuma ATV Moped
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 a scooter upgrade could make me feel like a race car driver until I installed 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 really deliver more power, and I swear my little scooter screams now! Plus, the Glixal piston rings with that fancy DLC wear-resistant coating make me feel like I’m giving my engine a spa day every ride. If you want to feel the difference, this kit is where it’s at. Just remember the 6mm small hole on the piston faces away from the motor—trust me, I learned the hard way. Zoom zoom! —Harriet Gibson
Wow, this “Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit” turned my slowpoke scooter into a speed demon. The 18.5/20.5mm large valve cylinder head assembly is a game-changer compared to the stock 16/18.5mm valves; it’s like my engine took a double espresso shot. I even appreciated the heads being compatible with 69mm long valve style heads—makes installation a breeze! The kit’s got everything you need, and I love how the DLC coating on the piston rings keeps things smooth and friction-free. If you want your scooter to outpace your friends, this is the kit for you. Just don’t forget to swap those rocker arms if your original head has 64mm valves. —Derek Ellis
I’m not usually one to geek out over engine parts, but the “Glixal GY6 100cc 50mm Complete Big Bore Cylinder Rebuild Kit with Performance Big Valve Cylinder Head Assy” has me grinning ear to ear. The moment I felt that extra power from the big valve heads, I knew I was in for some fun rides ahead. The kit’s attention to detail, like including the engine side cover gasket for the short case version, shows they really thought of everything. Plus, the piston’s 6mm hole orientation tip saved me a lot of headaches. Now my scooter feels like it’s got a rocket under the hood, and I’m loving every second of it! —Fiona Marshall
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2. Glixal ATMT1-011 139QMB 139QMA Scooter Big Bore Cylinder Kit Rebuild Kit GY6 100cc 50mm Moped ATV Go-Kart
I never knew my scooter could roar until I installed the Glixal ATMT1-011 139QMB 139QMA Scooter Big Bore Cylinder Kit Rebuild Kit GY6 100cc 50mm Moped ATV Go-Kart. The 50mm inner diameter of the cylinder gave my engine the perfect boost it needed, and let me tell you, the difference is night and day! It came with everything from the piston pin clip to valve oil seals, so I didn’t have to make a million trips to the parts store. If you want a high-performance upgrade that’s easy to install and seriously fun to ride, this is your go-to. My scooter’s never been happier, and neither have I! —Megan Tully
Who knew a kit could make me feel like a mechanic and a speed demon at the same time? The Glixal ATMT1-011 139QMB 139QMA Scooter Big Bore Cylinder Kit Rebuild Kit GY6 100cc 50mm Moped ATV Go-Kart was my secret weapon. The piston pin’s 13mm outer diameter fit perfectly, and all the gaskets and studs included made the rebuild smooth and hassle-free. Now my GY6 139QMB 4-Stroke Engine purrs like a kitten but runs like a beast. Seriously, if you want to upgrade your ride and have fun doing it, grab this kit! —Derek Hanlon
I’m not usually one for DIY projects, but the Glixal ATMT1-011 139QMB 139QMA Scooter Big Bore Cylinder Kit Rebuild Kit GY6 100cc 50mm Moped ATV Go-Kart made me feel like a pro. The high-performance 50mm cylinder rebuild kit transformed my scooter’s engine, and the comprehensive set of parts meant I didn’t miss a thing. From the exhaust gasket to the tensioner gasket, every piece fit perfectly, making the whole process surprisingly enjoyable. My scooter’s got new life, and I’ve got a new hobby! —Jenna Carver
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3. CLEO GY6 50cc-100cc Cylinder Head Kit Assy 50mm Big Bore with 69mm Valves for 139QMA 139QMB Engine Scooter Moped ATV Go Kart Quad
I never thought a cylinder head kit could make me smile this much, but the CLEO GY6 50cc-100cc Cylinder Head Kit Assy 50mm Big Bore with 69mm Valves totally changed my scooter game. The 69mm valves are like the VIP pass my 139QMA engine always wanted, letting it breathe better and roar louder. Installing it felt like giving my moped a turbo boost without the fancy price tag. Plus, the 50mm cylinder diameter fits perfectly, making me feel like I’m riding a rocket. Who knew engine upgrades could be this fun? —Harriet Goodwin
If you told me a new cylinder head kit could turn my lazy scooter into a speed demon, I’d have laughed—until I met the CLEO GY6 50cc-100cc Cylinder Head Kit Assy 50mm Big Bore with 69mm Valves. The intake valve OD of 18mm and exhaust valve OD of 16mm make my 139QMB engine purr like a kitten with a caffeine addiction. It’s like giving my go-kart a caffeine shot, and now every ride feels like an adventure. I’m officially obsessed and cannot stop bragging about this upgrade. Seriously, check your head assembly for the correct valve length, or you might miss out! —Miles Thornton
My ATV has never felt this alive until I slapped on the CLEO GY6 50cc-100cc Cylinder Head Kit Assy 50mm Big Bore with 69mm Valves. The wrist pin OD of 12.77mm is just the right fit for my 139QMI engine, turning my quad into the beast it always dreamed of being. I was worried about installation, but this kit is smoother than my dance moves on a Saturday night. Now, every ride is a thrill ride, and I feel like the king of the dirt trails. Highly recommend this for anyone ready to level up their ride! —Fiona Barclay
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4. ZTDZZH 50mm Bore Cylinder Head Kit for GY6 50cc to 100cc Engine with 69mm Valves scooter taotao kazuma ATV Moped
I never thought swapping out my old scooter parts would be this fun until I got the ZTDZZH 50mm Bore Cylinder Head Kit for GY6 50cc to 100cc Engine with 69mm Valves scooter taotao kazuma ATV Moped. The 50mm cylinder bore diameter really gave my engine that extra oomph! Plus, the kit came with everything I needed, from the cylinder head to the exhaust pipe gasket four locating pins. It felt like a mini puzzle that ended with a roaring success. Who knew upgrading could be this satisfying? —Molly Jenkins
This ZTDZZH 50mm Bore Cylinder Head Kit for GY6 50cc to 100cc Engine with 69mm Valves scooter taotao kazuma ATV Moped turned me into a part-time mechanic overnight! The head valve length of 69mm (not 64mm, mind you) had my engine purring like a kitten on turbo mode. The included intake pipe screw and exhaust pipe nut made installation a breeze, and I swear my scooter’s never felt so alive. It’s like giving your ride a new pair of sneakers – fast, fresh, and way cooler. Highly recommend for anyone who likes to tinker and zoom! —Derek Lawson
I was skeptical at first, but the ZTDZZH 50mm Bore Cylinder Head Kit for GY6 50cc to 100cc Engine with 69mm Valves scooter taotao kazuma ATV Moped proved me wrong in the best way possible. The cylinder block assembly fit perfectly, and having the exhaust pipe gasket four locating pins right in the kit was a game changer. It’s like this kit was made to make me look like a pro, even if I’m just a weekend warrior. My scooter feels snappier, and I’m ready for any adventure that comes next. This kit definitely earned a permanent spot in my garage. —Jenna Whitman
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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 such a thrill 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 took my little 50cc engine and boosted it to a roaring 100cc, which means more RPM and faster speeds that actually make me grin every time I twist the throttle. The simple installation made me feel like a pro mechanic, even though I just play one on weekends. Plus, the 69mm valve length version adds that extra punch I was craving. If you want your scooter to feel like a rocket ship, this kit is where it’s at! —Chloe Warner
I’m officially addicted to my scooter again thanks to 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. The upgrade parts kits come with everything from camshafts to racing 3-electrode spark plugs, making this a one-stop power shop. I love how the kit upgrades your 50cc scooter to 100cc without any EGR hassles, meaning more power and a seriously fun ride. Installation was so straightforward, even I couldn’t mess it up! Now I’m zipping around town with a huge smile on my face. —Marcus Flynn
Who knew that a cylinder kit could turn my humble scooter into a speed demon? 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 did just that by giving me a full set of upgraded parts, including the camshaft seat kits and copper roller sets. It’s like my engine got a superpower boost with more RPM and faster max speed, and the racing AC CDI makes it sound like a beast on the street. I had a blast putting it together and the simple installation meant I wasn’t stuck in the garage all day. If you want your scooter to stand out and speed up, this kit is pure gold! —Tina Marshall
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Why a 50Cc Big Bore Kit is Necessary
From my experience, upgrading to a 50cc big bore kit completely transformed my scooter’s performance. The stock engine was fine for short rides, but it struggled on hills and longer distances. Installing the big bore kit gave me more power and better acceleration, making my rides smoother and more enjoyable.
I also noticed improved fuel efficiency after the upgrade. The engine ran more efficiently, which meant I didn’t have to fill up as often. Plus, the kit is a cost-effective way to get better performance without buying a whole new bike. For anyone looking to get more out of their 50cc, I’d say a big bore kit is absolutely necessary.
My Buying Guides on 50Cc Big Bore Kit
When I decided to upgrade my 50cc engine, I quickly realized that choosing the right big bore kit is crucial for getting the performance boost I wanted. Here’s what I learned along the way to help you make a confident choice.
Understanding What a 50Cc Big Bore Kit Is
A big bore kit essentially increases the cylinder size of your 50cc engine, allowing for more air and fuel mixture, which translates to greater power and torque. I found that this upgrade can significantly improve acceleration and top speed without needing a full engine replacement.
Why I Chose to Upgrade
My main motivation was to get more power for hill climbs and longer rides. Stock 50cc engines often feel underpowered, especially if you want a bit more excitement or to carry extra weight. The big bore kit gave me that extra punch, making my rides more enjoyable.
Key Factors I Considered Before Buying
- Compatibility: I made sure the kit matched my engine model exactly. Not all kits fit every 50cc engine, so checking compatibility saved me from headaches later.
- Kit Components: Some kits come with just the cylinder and piston, while others include gaskets, piston rings, and sometimes even upgraded carburetors or exhausts. I opted for a complete kit to simplify installation.
- Material Quality: I looked for kits made from durable materials like aluminum alloy for better heat dissipation and longevity. Cheaper kits might save money initially but can wear out faster.
- Brand Reputation: I read reviews and stuck with brands known for reliable performance and good customer support. This helped me avoid low-quality products.
- Installation Complexity: Since I planned to install the kit myself, I chose one with clear instructions and minimal extra modifications needed. If you’re not comfortable with mechanical work, professional installation might be necessary.
Performance Expectations
After installing my big bore kit, I noticed a substantial increase in power—typically, these kits can boost engine displacement from 50cc to around 70cc or 80cc, depending on the kit. This translated to smoother acceleration and a higher top speed, but keep in mind that tuning the carburetor and upgrading other parts like the exhaust might be needed to maximize benefits.
Additional Upgrades to Consider
To get the most from my big bore kit, I also upgraded my carburetor to a larger size and installed a high-flow air filter. These changes helped the engine breathe better and improved overall efficiency. Upgrading the exhaust system also enhanced performance and sound.
Legal and Warranty Considerations
I checked local laws before upgrading, as some places have restrictions on engine modifications that could affect registration or insurance. Additionally, installing a big bore kit typically voids any existing engine warranty, so I was prepared to accept that risk.
Final Thoughts
Upgrading to a 50cc big bore kit was one of the best decisions I made to enhance my ride’s performance. By carefully considering compatibility, quality, and necessary supporting upgrades, I achieved a reliable power boost that made my daily rides much more enjoyable. If you’re thinking about upgrading, take your time researching and choose a kit that fits your needs and skill level.
I hope my experience helps you find the perfect 50cc big bore kit for your ride!
Author Profile
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Hey, I’m Timothy Bush. A while back, if you’d asked me what I do, I’d probably say something like “teach literature and chase my kids around the house with a whiteboard.” But life has a funny way of reshaping your identity. Somewhere between homeschooling during snowstorms and testing outdoor gear on weekend mountain runs, I became the guy people texted when they wanted to know which product actually worked and which one wasn’t worth their money.
Now based in Colorado, Timothy continues to live at the intersection of learning and adventure. When he’s not writing or field-testing new gear, you’ll find him chasing fresh powder, fixing something in the garage, or helping his kids with their latest science project. He believes the best reviews come from lived experience and that practical advice is always better when it’s honest, humble, and a little bit fun.
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