Engines and Components› Engines, Blocks and Components

Lifan

125cc 4-Stroke Engine with 78mm Cylinder

$529.00

SKU: EN12-78MM

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

The Lifan EN12-78MM is a 125cc, 4-stroke, single-cylinder engine designed for pit bikes and small motorcycles. It features air cooling, a 2-valve configuration, and a 78mm tall cylinder. This engine includes a 4-speed semi-automatic transmission with a bottom-neutral, four-up shift pattern and a kick-start option.
Show original supplier description
The Lifan EN12-78MM engine is a 125cc, 4-stroke power plant designed for pit bikes and small motorcycles, offering an upgrade path for models like the Honda XR50/70 and CRF50/70. This air-cooled, single-cylinder engine features a 2-valve, 78mm tall cylinder design, providing a displacement of 124cc. Equipped with a 4-speed semi-automatic transmission, the EN12-78MM operates with a bottom-neutral, four-up shift pattern (N-1-2-3-4) and includes both kick-start and electric start capabilities. It utilizes a CDI ignition system and comes with a front drive sprocket that accepts a larger 20mm x 17mm shaft. The recommended fuel is unleaded gasoline with a minimum of 91 octane, and the engine oil specification is 10W-40 petroleum-based, non-synthetic. When upgrading certain Honda models such as the XR50/70 or CRF50/70, aftermarket footpeg mounts and tank spacers may be required. For optimal performance, the use of an aftermarket exhaust system is also suggested. These related components are available from TBoltUSA.com.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandLifan
Part NumberEN12-78MM
CategoryEngines and Components
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy