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Piranha 140cc Engine
fits Pit Bikes and other Minis

Vital Information
Part No WHS-1143
Stock Level 5 Left
Choose Options

**Signature required shipment**

This is the famous Piranha 140cc Engine, often referred to as the YX140cc. This is a super sturdy and very strong running engine. This is our ALL TIME best selling engine

See picture for included parts. Engine available as pictured. We've had tremendous luck with this engine, and it's a great replacement engine or for builds & projects.

*AMA RULE BOOK Eligible YX 1P56FMJ (140cc)
JR mini Class 2: 7-15 years old – 150cc Mini Speedway

Engine Kit Includes:

  • Engine
  • Intake
  • CDI
  • Coil
  • Harness
  • Kicker 16mm
  • Shifter
  • Carburetor
  • 15T front drive sprocket

Displacement 140cc
Engine Type Air Cooled, Single-Cylinder, 2-valve, 4-stroke
Bore/Stroke 56mm x 57mm
Final Drive Chain
Fuel Delivery Nibbi 19mm 
Fuel Unleaded / 91 Octane
Recommended Engine Oil 10W-40 Petroleum Based (Nonsynthetic)
Kick Start Yes (16mm)
Electric Start No
Auxiliary Output (lighting) Yes
Transmission 4-Speed Manual 4-Up
Shift-Pattern Four-speed Transmission: N-1-2-3-4
Clutch Rear 5 plate manual

For lighting setups:

  • Voltage regulator simple harness type 1 - TRC-0797
  • Voltage regulator/rectifier 6V type 1 - TRC-0503
  • Voltage regulator/rectifier 12V type 1 - TRC-0127

Recommended for your application:

Honda XR50/CRF50:

  • CRF50/XR50 tank spacer kit - TRC-1955
  • Peg mount w/ pegs setup - TRC-4958
  • Throttle cable - TBW0301
Honda XR70/CRF70:

  • Peg mount with peg set up - TRC-4958
  • Throttle cable - TBW0301
Honda CT70:

  • Peg mount w/ pegs setup - TRC-4958
  • Dual feed petcock for ATC70 CT70 Z50 - TBW0133
  • CR type universal throttle 1/2 turn - W-70-1056
  • T3 throttle cable for 20-28mm carb - TRC-1142
Honda Z50:

  • TBparts race petcock for Z50 69-78 - TBW0355
  • TBparts 12-way rotating spacer - TBW1487
Honda ATC70: 

  • Dual feed petcock - TBW0133

Not Included:

  • Skid plates
  • Exhaust
  • Air filter
  • Throttle Cable
  • Clutch lever
  • Clutch cable

Note: We suggest using an aftermarket exhaust to obtain maximum performance.


  • You may want to consider setting up the bike on a stand for a solid starting location at first until your confident
  • Turn on Both Fuel and Choke
  • DO NOT open the throttle (do NOT turn the throttle)
  • Move the starter down until it gets stiffer, your looking for top dead center
  • Let the starter come back up and give a full strong swift kick ALL the way thru
  • REPEAT (If necessary)
  • When warm just do not use the choke

Flooded Engine:
IF your flooded , pull the plug, kick it over about 10 times WITH THE PLUG OUT
Put in a NEW PLUG

For ease of starting:
You may want to consider our TRC EZ START HIGH PERFORMANCE CDI
Part No. TRC-9745

One more thing:
At times it helps to just crack the throttle a tiny bit to let air in.

Available Options:

Clutch Cable:

Clutch lever:

Exhaust Gasket:


Kill Button:


Uni Air Filter:

(29 Reviews)

Since 2004, every purchase from TBolt USA includes access to technical support from our staff of experts and our online Pit Bike Technical Info Database!

We have all necessary support parts on hand.

Most orders ship same, or next business day, unless otherwise noted above.