Skip to content
Keystone Cycle Parts
  • Home
  • Shop By Bike
    KLX140
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    KLX110
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    CRF110
    • Engine
    • Wheels
    • Controls
    • Chain/Sprockets
    • Suspension
    • Other
    • Plastic/Tank/Body
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Exhaust
    • Pegs/Mounts/Skid Plates
    CRF125F
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    XR100/CRF100
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    CRF150F
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    XR50/CRF50
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    Z50
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    XR70/CRF70
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    XR80/CRF80
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    TTR110
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    TTR125
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    TTR50
    • Controls
    • Engine
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    CT70
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    ATC70
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    TRX90
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    Grom/Monkey
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    Z125
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    BBR Framed Bikes
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    2Stroke
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
    Other Bikes
    • Engine
    • Controls
    • Plastic/Tank/Body
    • Chain/Sprockets
    • Suspension
    • Other
    • Intake/Carbs
    • Accessories/Tools
    • Billet
    • Maintenance
    • Wheels
    • Exhaust
    • Pegs/Mounts/Skid Plates
  • Gear/Apparel/Merch/BOB
    • BOB The Cooler Company
    • KCP Apparel/Merch
    • Gear
  • Davey's Deals
  • Events
  • About Us
  • Contact
  • Home
  • Shop By Bike
    Shop By Bike
    • KLX140
      KLX140
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • KLX110
      KLX110
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • CRF110
      CRF110
      • Engine
      • Wheels
      • Controls
      • Chain/Sprockets
      • Suspension
      • Other
      • Plastic/Tank/Body
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • CRF125F
      CRF125F
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • XR100/CRF100
      XR100/CRF100
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • CRF150F
      CRF150F
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • XR50/CRF50
      XR50/CRF50
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • Z50
      Z50
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • XR70/CRF70
      XR70/CRF70
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • XR80/CRF80
      XR80/CRF80
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • TTR110
      TTR110
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • TTR125
      TTR125
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • TTR50
      TTR50
      • Controls
      • Engine
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • CT70
      CT70
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • ATC70
      ATC70
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • TRX90
      TRX90
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • Grom/Monkey
      Grom/Monkey
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • Z125
      Z125
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • BBR Framed Bikes
      BBR Framed Bikes
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • 2Stroke
      2Stroke
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
    • Other Bikes
      Other Bikes
      • Engine
      • Controls
      • Plastic/Tank/Body
      • Chain/Sprockets
      • Suspension
      • Other
      • Intake/Carbs
      • Accessories/Tools
      • Billet
      • Maintenance
      • Wheels
      • Exhaust
      • Pegs/Mounts/Skid Plates
  • Gear/Apparel/Merch/BOB
    Gear/Apparel/Merch/BOB
    • BOB The Cooler Company
    • KCP Apparel/Merch
    • Gear
  • Davey's Deals
  • Events
  • About Us
  • Contact
L o g   i n  

Don't have an account? Sign Up!

TB Parts 138cc Big Bore Kit - 125cc 54x54mm 14mm pin Chinese engines
TB Parts 138cc Big Bore Kit - 125cc 54x54mm 14mm pin Chinese engines

TB Parts 138cc Big Bore Kit - 125cc 54x54mm 14mm pin Chinese engines

TBW9225

$163.99 Liquid error (snippets/product-price line 23): Computation results in '-Infinity' Unit price / Sold out

Shipping calculated at checkout

Quantity

 
 
This item is a recurring or deferred purchase. By continuing, I agree to the cancellation policy and authorize you to charge my payment method at the prices, frequency and dates listed on this page until my order is fulfilled or I cancel, if permitted.
Description

138cc (57mm) Bore Kit for Chinese 125cc Engines with Big Valve Cylinder Heads (Lifan, V2, etc):

  • 57x69mm cylinder with steel liner
  • High compression large dome 57mm piston with rings, 14mm pin, & clips
  • Head gasket kit

This will make a very nice difference in performance over your stock setup. Additionally, it is a very quick and easy upgrade as it does not require case boring. We found the right level of compression for increased performance while also keeping reliability in mind.  The 138cc bore kit includes a 57mm bore cylinder, light weight high revving piston and a head gasket kit. Bolt on power!

Important Note: This kit will only work on Chinese/Lifan style 125cc engines with a 69mm cylinder (base to Deck), 54mm stroke, 14mm piston wrist pin, and clutch basket is on the crankshaft. There are so many Chinese brands/models that you absolutely need to know your stroke and piston wrist pin size. Unfortunately, we are unable to tell you what you have based on a brand name as there are so many unknown Chinese brands.  This kit is also recommended for use only with big valve heads such as the common Lifan head with 27/23mm valves or our V2 Race Head for Chinese engines.

Installation Notes: Don’t use the original o-rings between the head and cylinder (not needed) but do use the large o-ring at the bottom of the cylinder between the cylinder and the engine case at the oil return. The new head gasket has RTV gasket built in.

TB Parts 138cc Big Bore Kit - 125cc 54x54mm 14mm pin Chinese engines

TB Parts 138cc Big Bore Kit - 125cc 54x54mm 14mm pin Chinese engines

$163.99 Liquid error (snippets/product-price line 23): Computation results in '-Infinity' Unit price / Sold out

Recommended Products

Follow me
Help Center
  • Contact Us
  • Policies
  • Search
  • Keystone Logos

© 2025, Keystone Cycle Parts, Powered by Shopify

en
  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa
  • Menu
  • Search
  • Home
  • Account
  • Cart
Cart

Your cart is empty

You have not added any cart items yet.

C o n t i n u e   s h o p p i n g  
  • Refresh page
  • New window