MADE IN THE UNITED STATES OF AMERICA

ROAD RACE ENGINE PERFORMANCE PACKAGES

Modern four-stroke engines are remarkable things. These technological marvels are the ultimate in performance and reliability for average riders as well as racers. Large doses of torque and linear power delivery make four-strokes the number one choice for road racing. In recent years the weight and reliability of these engines have made great strides and today, four strokes are the obvious choice.

Developing four-stroke power, however, is a study in incremental-ism. All of the reciprocating parts create friction and heat that detract from performance. As a result of this dynamic, building up the power is best approached in stages.

These engines are, in essence, many parts that together create a whole. If all the parts work in unison and in concert, large increases in reliable power occur. If only a few pieces of the whole are installed, you may create more problems than you will solve. All the pieces have to work together or you will concentrate stress loads and other negatives into specific areas, possibly ending with a Catastrophic Engine Failure.

At Yoshimura, we have been building four-stroke racing engines for over 50 years. We understand that your engine is the sum of many parts. We do not simply throw a big cam in, pop up the compression, and create a time bomb. Depending on which stage of engine modification you choose, we build power at self-sustaining, balanced levels.

We have our own in-house Isotropic Surface Finishing Process (ISF) department where we can blueprint your engines gear-sets just like Formula-1 machines. This technology not only let's your engine run "freer", but also lowers operating temperatures through decreased friction and proper interaction of reciprocating parts. We also have twelve Dyno cells (including two state of the art Onno-Soki units) and advanced computer diagnostics in everything from flow to metallurgical failure rates. There is no guessing here.

STAGE 1 PACKAGE

 

INCLUDED LABOR

  • Disassemble, Inspect, and Re-assemble Motor
  • Valve Job
  • Mill Cylinder Head to optimize compression ratio
  • Piston Modification

INCLUDED COMPONENTS

  • Cylinder Head Gasket
  • OEM Valve Springs
  • Valve Seat Shims
  • New Bearings, Gaskets, Circlips

ADDITIONAL OPTIONS

  • Port and Polish Cylinder Head with Valve Job
  • ST-R Type-S Camshaft Set
  • Forged High Compression Pistons
  • Precision Machined Top Retainers
  • Precision Machined Valve Cotters
 
   

STAGE 2 PACKAGE

 

INCLUDED LABOR

  • Disassemble, Inspect, and Re-assemble Motor
  • Port and Polish Cylinder Head with Valve Job
  • Mill Cylinder Head to optimize compression ratio
  • Piston Modification
  • ISF Service

INCLUDED COMPONENTS

  • ST-R Type-S Camshaft Set
  • Performance Cylinder Head Gasket
  • OEM Valve Springs
  • Valve Seat Shims
  • New Bearings, Gaskets, Circlips
  • Works Edition Engine Plug Kit

ADDITIONAL OPTIONS

  • CNC Porting Valve Job
  • Forged High Compression Pistons
  • Precision Machined Top Retainers
  • Precision Machined Valve Cotters
  • Install High Performance Valve Seats
  • Lighten / Polish and Balance Crankshaft
 

STAGE 3 PACKAGE

 

INCLUDED LABOR

  • Disassemble, Inspect, and Re-assemble Motor
  • CNC Porting / Valve Job
  • Install High Performance Valve Seats
  • Mill Cylinder Head to optimize compression ratio
  • Lighten / Polish and Balance Crankshaft
  • ISF Transmission Assembly and Shift Mechanism

INCLUDED COMPONENTS

  • ST-R Type-S Camshaft Set
  • Forged High Compression Pistons
  • Performance Cylinder Head Gasket
  • OEM Valve Springs
  • Valve Seat Shims
  • Ceramic Hybrid Transmission Bearings
  • New Bearings, Gaskets, Circlips
  • Works Edition Engine Plug Kit

ADDITIONAL OPTIONS

  • Titanium Connecting Rods
  • Oversize Titanium Intake Valves
  • Oversize Titanium Exhaust Valves
  • Precision Machined Top Retainers
  • Precision Machined Valve Cotters
  • DLC Treated Light-weight Intake Tappets
  • DLC Treated Light-weight Exhaust Tappets
 
 
FOR MORE INFORMATION CONTACT:
Dave Sanders
Engine Building Services
phone (909) 628-4722 Ext: 430
email dsanders@yoshimura-rd.com