64mm Motorcycle Piston Kit – Zongshen 125cc / Lifan 138cc

64mm motorcycle piston kit with pin, circlips and rings

64mm Motorcycle Piston Kit – Zongshen 125CC / Lifan 138CC Horizontal Air-Cooled Piston, Rings & Pin

Dhs. 113.77

64mm Motorcycle Piston Kit for Zongshen 125cc and Lifan 138cc Horizontal Engines

This 64mm motorcycle piston kit is a replacement piston and ring set listed for Zongshen 125cc and Lifan 138cc horizontal, air-cooled engines. The piston measures 64 mm across and 49 mm tall, runs a 15 mm piston pin, and is made from high-purity aluminum. At Easy Life Markets we sell it as a complete piston kit with rings and pin, ready for a top-end rebuild.

Horizontal engines, with the cylinder lying almost flat and pointing forward, are the layout used on a huge number of small motorcycles, pit bikes, ATVs and utility bikes. Zongshen and Lifan are two of the best-known makers of these engines, and their designs are used across many brands, so the same piston can turn up in bikes with very different badges on the tank.

Why You Would Replace the Piston

These engines are simple and tough, but they do wear, especially if they have been ridden hard, run low on oil or fed dusty air through a tired filter. A new piston and rings are usually needed when you notice:

Smoke from the exhaust and oil disappearing from the sump
Hard starting and poor idle
Less power on hills or with a passenger
A knocking or slapping noise from the cylinder
A piston that has seized or scuffed after overheating

Before you order, pull the cylinder and check the bore. If the cylinder wall is smooth and within size, a piston kit on its own is often enough. If it is scored, the cylinder needs to be replaced or rebored.

Key Features

High-purity aluminum piston
64 mm piston diameter and 49 mm height, shown on the dimension photo
15 mm piston pin
Complete ring set for sealing and oil control
Designed for horizontal air-cooled engines

What Is Included

As shown in the product photos, the kit includes:

1 x piston
1 x set of piston rings
1 x piston pin
2 x piston pin circlips

Specifications

Product type: Motorcycle piston and rings kit
Listed engines: Zongshen 125cc and Lifan 138cc horizontal, air-cooled
Piston diameter: 64 mm (6.4 cm)
Piston height: 49 mm (4.9 cm)
Piston pin size: 15 mm
Material: High-purity aluminum
Quantity: 1 kit
SKU: CJJT142889401AZ

Check the Size Before You Buy

This is the most important part of buying any piston for a horizontal engine. Engines in this family were built in many sizes and by many factories, and the displacement badge on the bike is not always a reliable guide to the bore inside. Some engines have also been bored out or fitted with big bore kits over the years. So please check these three numbers against your engine rather than going by the model name alone:

Bore: measure the inside of your cylinder. This piston is 64 mm in diameter.
Piston height: measure your old piston from the crown to the bottom of the skirt. This one is 49 mm.
Pin diameter: measure your old pin. This kit uses a 15 mm pin.

It also helps to compare the crown shape and valve reliefs with the photos. If all three numbers match, the 64mm motorcycle piston kit is the one you want. If one of them does not, send us your measurements and we will tell you honestly whether this part suits your engine.

Installation Advice

Fitting a piston kit is a straightforward job for most home mechanics with a set of metric sockets, a torque wrench and a service manual. A few tips:

Cover the crankcase opening with a clean rag before you remove the old circlips.
Check the ring end gaps inside the cylinder before fitting them to the piston.
Install the piston rings with markings facing up and space the gaps evenly around the piston.
Follow the direction mark on the piston crown when you fit it to the connecting rod.
Coat the piston, rings and cylinder with fresh engine oil before assembly.
Replace the base and head gaskets rather than reusing the old ones.
Break the engine in gently and change the oil after the first short run.

Helping Your New Piston Last

A new piston will only last as long as the conditions inside the engine allow. Most piston failures on horizontal engines come down to a handful of causes, and all of them are easy to avoid. Keep the air filter clean and properly sealed, because dust drawn past a loose filter wears rings and cylinder walls quickly. Change the oil on schedule, and check the level often, since these small engines hold very little oil. Make sure the carburetor jetting is not too lean, especially after fitting an aftermarket exhaust or intake, as a lean mixture runs hot and can scuff a piston. Finally, let the engine warm up for a minute before riding hard. Looking after these basics will get far more life from your rebuild.

Who This Kit Suits

This kit is aimed at owners of small motorcycles, pit bikes and utility bikes with Zongshen or Lifan horizontal engines, and at repair shops that keep common pistons on hand. It is a cost-effective way to bring back compression and stop oil burning on an engine that is otherwise healthy.

Order the 64mm Motorcycle Piston Kit at Easy Life Markets

You can buy this piston kit right here. The current price and availability are shown on this page. If you would like us to check your measurements first, get in touch with our customer service team. Please also take a look at our return and refund policy before ordering.