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YX140 Cylinder Head Assembly for 1P56YMJ 1P56FMJ 140cc 150cc Pit Dirt Bike
YX140 Cylinder Head Assembly for 1P56YMJ 1P56FMJ 140cc 150cc Pit Dirt Bike
5.0 / 5.0
(1) 1 total reviews
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Product Overview
Boost your engine's performance with the YX140 Cylinder Head Assembly Kit. Specifically engineered for high-performance 140cc and 150cc 4-stroke horizontal engines, this kit is a direct replacement for YX (YinXiang) power plants. Featuring optimized intake and exhaust ports, this head is designed to handle high-intensity riding while delivering maximum power output and superior cooling for your Pit Bike or ATV.
Product Compatibility
This cylinder head is a specialized fit for YX (YinXiang) Series 4-Stroke Horizontal Engines.
| Engine Type | Compatible Engine Codes |
| YX 140cc / 150cc | 1P56YMJ, 1P56FMJ, 1P56FMJ-5 |
| Vehicle Compatibility | Pit Bikes, Dirt Bikes, ATVs, Quads, and Custom Builds |
| Popular Brands | SSR, Piranha, Pitster Pro, Stomp, Demon X, Apollo |
Specifications
| Feature | Measurement |
| Engine Cycle | 4-Stroke |
| Inlet Valve Diameter | 27mm (1.06") |
| Exhaust Valve Diameter | 23mm (0.9") |
| Valve Stem/Pole | 5mm (0.2") |
| Dimensions (L x W x H) | 155mm x 150mm x 110mm |
| Material | Heat-Treated Aluminum Alloy |
Key Features
- Precision Machined: Crafted from high-grade aluminum alloy with a specialized heat treatment for extreme temperature resistance.
- Enhanced Airflow: Optimized intake and exhaust passages significantly improve volumetric efficiency and power output.
- Race-Ready Durability: Sturdy structure designed to withstand high-intensity racing environments and long-term mechanical stress.
- Superior Heat Dissipation: Engineered to maintain stable operating temperatures, protecting internal components during high-load use.
- Direct Performance Upgrade: Fully compatible with 1P56YMJ series engines, providing a reliable and robust solution for engine rebuilds.
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Fitment FAQ
Will this part fit my specific model and year?
This cylinder piston kit is intended for This cylinder head is a specialized fit for YX (YinXiang) Series 4-Stroke Horizontal Engines .; Engine Type; Compatible Engine Codes; YX 140cc / 150cc; 1P56YMJ, 1P56FMJ, 1P56FMJ-5; Vehicle Compatibility; Pit Bikes, Dirt Bikes, ATVs, Quads, and Custom Builds. Key physical/spec details from the product data include Inlet Valve Diameter: 27mm (1.06"), Exhaust Valve Diameter: 23mm (0.9"), 140cc. 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 YX140 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 Inlet Valve Diameter: 27mm (1.06"), Exhaust Valve Diameter: 23mm (0.9"), 140cc. If any connector, mounting point, size, or year detail is different, confirm fitment before installation.
Fitting was easy and my mate who did the work was more than happy.The build quality is good and the machining and finish is good.Once the engine was refitted he even did some tweaking to the fueling.First start took about 30 to 40 seconds but it now it fires up instantly.We have only run the bike to the end of the road so far but it definitely feels faster and throttle responses are crisp.