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Fuel Moto M8 128" Outlaw Piston & Cylinder Big Bore 114 117 engines

NOTE: This product has the following shipping restriction(s):
  • This product cannot ship to California.
Pricing: $1,199.95

Customize Your Item

- Choose cylinder finish -
 * required
- Please select your piston -
 * required
NOTE: This product has the following shipping restriction(s):
  • This product cannot ship to California.


The Fuel Moto M8 128" Outlaw piston & cylinder kits takes your 114" or 117" M8 engine to 128" with no engine case boring required. Includes special application, high compression pistons with choice of 11.5:1 or 12.0:1 compression. Pistons were designed for Fuel Moto by CP Carrillo race department with optimized skirt and barrel profile, and feature Calico premium skirt coating. Kit also includes new Extreme Duty cylinders (made in USA), and Cometic MLS heads & base gaskets. This kit works on 2017-later Milwaukee-Eight 114" & 117" 4.5" stroke engines (air cooled & twin cooled) Touring and Softail. 

The Fuel Moto M8 128" Outlaw high compression kit includes the following: 

Custom Fuel Moto / CP Carillo Forged Pistons

Custom CP Carrillo Pistons

Special application, custom CP Carrillo pistons, choice of 11.5:1 or 12.0:1 compression ratio with optimized skirt and barrel profile, Calico premium skirt coating. These FM custom pistons use CP's premium X-Forging for reduced friction and maximum durability. The ring end gap is already set and are simply ready to be installed.


Fuel Moto Precision Bored Cylinders

New Extreme Duty cylinders

The Fuel Moto M8 128" Outlaw big bore kit includes new Extreme Duty cylinders with high strength ductile iron sleeves, bore/hone finish work is done on OEM level machinery to exact tolerances. Cylinders are available in black with silver polished highlights or in CVO granite finish with polished highlights. Manufactured by S&S Cycle in Viola, WI USA. MLS head & base gaskets are included. 


What else do I need?

This kit is designed for big horsepower, you will need an exhaust system, air cleaner, EFI tuner, and clutch spring and/or lockup to support the appropriate power level of this kit. Milwaukee-8 engines also require larger fuel injectors. Fuel Moto engine kits require installation by a qualified mechanic with experience in engine building and the appropriate tools to check all clearances & tolerances during engine assembly following the OEM service manual procedures and any additional instructions provided. You will need a OEM service manual and some specialty tools such as a inner cam bearing removal/install tool. These engine kits also require comprehensive tuning, we will supply the appropriate FM base tune. Check our FM University site for helpful tips and info.

Unlimited Technical Support From Fuel Moto

You have done all of your research but maybe you still have a question. The technicians at Fuel Moto have the answers and would welcome your call. With every Fuel Moto big bore kit purchase we include unlimited technical support. Shoot us an email at or give us a call at 920-423-3309 - we will work together to get you up and running.


Professional turn key Installation:

available at our location including the complete kit, break in & dyno tune on our state of the art dyno. (*does not include EFI tuning device, exhaust system, throttle body, injectors or other associated parts such as oil & filter)

Application List

Fitment for Fuel Moto M8 128" Big Bore Kit


  • Fuel Moto
  • New


Shipping Information

  • Item Requires Shipping
  • 30.0 lbs.
  • W21.0000” x H14.0000” x L14.0000”
  • This item ships in its own box.