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50mm Piston Rings Kit for GY6 50cc 100cc Big Bore Engine
50mm Piston Rings Kit for GY6 50cc 100cc Big Bore Engine
4.0 / 5.0
(1) 1 total reviews
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Product Overview
This premium 50mm Piston Kit is the ultimate performance upgrade for GY6 139QMB engines. Specifically designed for 100cc Big Bore Cylinder assemblies, it allows riders to significantly increase displacement and torque, restoring and enhancing the power output of scooters, ATVs, and pocket bikes.
Product Compatibility
This kit is a dedicated replacement for GY6 50cc engines that have been upgraded with a 50mm bore cylinder.
| Vehicle Type | Popular Compatible Brands & Models |
| Scooter / Moped | TaoTao, Jonway, Roketa, VIP, Wolf Brand, Ice Bear |
| ATV / Quad | 100cc Chinese 4-Stroke Quads, Kids ATVs |
| Engine Series | GY6 139QMB, 1P39QMB (Large Bore Upgrade) |
| Pocket Bike | Various 100cc 4-Stroke Mini Bikes |
Specifications
| Component | Metric Measurement | Imperial Measurement |
| Piston Diameter | 50mm | 1.97" |
| Wrist Pin Diameter | 13mm | 0.51" |
| Engine Platform | GY6 139QMB (100cc) | -- |
| Engine Stroke | 4-Stroke | -- |
| Material | High-Grade Heat-Resistant Alloy | -- |
Key Features
- Maximum Power Upgrade: Massive 50mm diameter increases engine displacement to 100cc, delivering a major boost in acceleration and top speed.
- Advanced Heat Dissipation: Engineered with a specialized structure to efficiently manage high temperatures in air-cooled engines.
- Superior Durability: Constructed from high-toughness, rustproof materials designed to withstand the stress of high-compression performance.
- Precision Seal Performance: Includes premium rings that ensure a perfect airtight seal, maximizing combustion efficiency and reducing oil consumption.
- Reliable Long-Life Service: Rigorously tested for wear resistance to provide consistent performance over long-distance rides and heavy-duty use.
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Fitment FAQ
Will this part fit my specific model and year?
This cylinder piston kit is intended for This kit is a dedicated replacement for GY6 50cc engines that have been upgraded with a 50mm bore cylinder.; Vehicle Type; Popular Compatible Brands & Models; Scooter / Moped; TaoTao, Jonway, Roketa, VIP, Wolf Brand, Ice Bear; ATV / Quad; 100cc Chinese 4-Stroke Quads, Kids ATVs. Key physical/spec details from the product data include This kit is a dedicated replacement for GY6 50cc engines that have been upgraded with a 50mm bore cylinder., GY6 139QMB, 1P39QMB (Large Bore Upgrade), Piston Diameter: 50mm. Use the compatibility table and product photos together before ordering.
Do I need to match the OEM part number?
Yes. If your original part has a stamped OEM or manufacturer number, match that number first before ordering. For this cylinder piston kit, also compare the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. This is especially important for GY6/Roketa/TaoTao GY6 models because similar model names can use different parts by year or trim.
What models or situations does this part not fit?
Do not order this cylinder piston kit for machines outside the listed compatibility, or for units with different bore sizes, piston-pin diameters, stroke lengths, stud spacing, or gasket patterns. Do not rely only on the model name or engine size.
What should I check before ordering?
Before ordering, compare your original part with the photos and check the bore diameter, piston-pin size, gasket pattern, stud spacing, engine code, stroke type, and cylinder height. Recheck listed specs such as This kit is a dedicated replacement for GY6 50cc engines that have been upgraded with a 50mm bore cylinder., GY6 139QMB, 1P39QMB (Large Bore Upgrade), Piston Diameter: 50mm. If any connector, mounting point, size, or year detail is different, confirm fitment before installation.
80cc upgrades to 50cc GY6 motors seem to get more attention than larger 100cc upgrades, but there are still a lot of 100cc kits out there. The larger kits put more stress on the motor than their smaller upgrades--in one motor I took apart, the 100cc piston was so wide that it started knocking against the inside of one of the engine cases on every downstroke, causing premature wear and tear on the piston and the crankshaft. Still, there's no denying the power that comes from extra displacement.This replacement piston kit is designed for 100cc big bore kits where the piston has suffered some damage (possibly from running too lean or from physical damage like that one that struck the engine case repeatedly). The kit includes the pistons, the rings, the connecting bearing for the crankshaft, and a fresh set of springs to hold everything together. The piston itself is a cast piston with nicely polished sides and a slightly nubbly finish for the top.I found this kit attractively priced for what it is--a smaller fix rather than a complete overhaul for a motor. My expectation is that it would work well in a properly sized (50mm) bore and would provide good performance. Note that you will need fresh head and barrel gaskets as well after changing the piston. You could try reusing what you have, but I doubt you'd have very good compression.Recommended.