Check out our big bore kits below!
PROBLD GY6 171cc BIG BORE KIT WITH CARBURETOR
PROBLD GY6 171cc BIG BORE KIT NO CARBURETOR
PROBLD GY6 CAMSHAFT
61MM BIG VALVE CYLINDER HEAD
190cc BIG BORE KIT PACKAGE
63MM 180cc BIG BORE KIT
63MM BIG VALVE CYLINDER HEAD
GY6 ENGINE STAND
In this comprehensive guide, we will explore the essentials of the GY6 engine, specifically focusing on selecting the correct big bore kit. This information is tailored for enthusiasts with 125cc or 150cc GY6 engines found in scooters, buggies, ATVs, or small motorcycles. We will clarify the distinctions between various kits and help you avoid common mistakes in your selection process.
Key Topics Covered in the Video
1. Engine Identification
• The importance of identifying whether you have a GY6 engine or a different one (50cc engines have different parts).
• Links in the description provide deeper insight.
2. Choosing the Right Big Bore Kit
• Discussion of kits from eBay or Amazon compared to reputable brands.
• Understanding piston design differences: flat-top vs. dome pistons.
• Forged vs. cast pistons: characteristics, advantages, and disadvantages.
3. Components of a Big Bore Kit
• Types of kits you might encounter:
• 171cc Big Bore Kit: The pros and cons of drop-in and non-drop-in options.
• Cylinder compatibility based on kit types.
Important Discriminators in Big Bore Kits
Drop-in vs. Non-Drop-in Kits
• Drop-in Kits:
• Allow seamless installation without needing to bore engine cases.
• Typically the most preferred option for ease and efficiency.
• Non-Drop-in Kits:
• Require extensive modifications, including case boring.
Kit Examples:
• Pro Build Kit: Drop-in compatible, comes pre-assembled.
• eBay Kit: Not drop-in compatible, requires assembly.
Piston Types Explained
The choice between a forged piston and a cast piston significantly impacts engine performance and longevity.
• Cast Pistons:
• Affordable and well-suited for high mileage.
• Less performance-oriented but reliable for OEM machines.
• Forged Pistons:
• Superior performance.
• Best for high-end applications but may cause piston slap in daily-use engines.
Comparison of Piston Types:
• Cast Pistons: Made from molten aluminum, good for long-term mileage but with mediocre durability.
• Forged Pistons: Made from billet aluminum, excellent for racing applications, with high but variable durability.
Additional Kit Specifications
Compression Considerations
• Dome Pistons vs. Flat Pistons
• Dome pistons provide higher torque but may limit engine revs due to increased compression.
• Flat pistons allow for higher RPMs, offering a balanced performance.
Base Gaskets
• High-performance kits like Pro Build come with multiple gaskets.
• A thinner gasket increases compression, while a thicker one maintains standard compression.
Common Pitfalls
1. Misidentifying Kit Types
• Recognizing visual cues prevents purchasing the wrong components (e.g., distinguishing cast from forged pistons).
2. Compatibility with Engine Cases
• Kits larger than 61mm generally require modifications to engine cases to fit properly.
Performance Enhancements
To maximize the potential of your GY6 engine, consider these upgrades:
• Big Valve Cylinder Heads: Enhance airflow for better combustion.
• Performance Camshafts: Optimized for low to mid-range torque.
• Ceramic-Coated Cylinders: Improve heat management, especially for larger kits (over 61mm).
Going Beyond 171cc
• Options for larger displacements include 180cc or 205cc kits, depending on performance goals.
• Stroker Cranks allow for displacements exceeding 205cc but require extensive modifications.
Conclusion
Choosing the right big bore kit for your GY6 engine is crucial for optimizing performance and reliability. Make informed decisions based on thorough research and understanding of components like pistons, cylinder heads, and how they impact engine behavior.
By knowing the differences between drop-in and non-drop-in kits, forged vs. cast pistons, and performance-enhancing modifications, you can confidently build an engine that meets your specific needs.
Check the links in the description for more information on kits and parts that best suit your GY6 engine build. Thanks for tuning in, and we’ll see you in the next video!