Yamaha YZF R1 Engine

1998 to present

Donor motorcycle

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This engine seems to be a popular choice recently for individuals building new cars. It's advantages include modern technology (five valves per cylinder) enabling high stock horsepower in a lightweight package.

The engine can also be found fairly easily with low mileage at a moderate price ($1300 to $2400, depending upon mileage and negotiating techniques). Being a contemporary engine, there are also various tuners and aftermarket suppliers catering to the enthusiasts' desire for more power.

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Stock carburetors from the motorcycle engine.

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A shot of the top of the head.

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A donor engine and typical items included in a "car kit".

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Eric Liebscher's race prepared R1, with Keihn flat slide carburetors and a Beasley dry sump system.

Note that the transmission uses a cable to operate the clutch by pulling on a lever. So, for most car applications, conversion from cable to hydraulic actuation with be desired. A variety of slaves cylinders can be used for the adaptation. Lee Stohr is using a Wilwood pull type slave cyclinder which costs about $58. "We even use the stock lever on the engine. Just drill out a rivet that holds the stock cable in place."

Billetanium R & D (427 Grand Ave. #B, San Jacinto, CA 92583, 909-654-2089) sells a pull slave cylinder from a hydraulic conversion kit originally designed for the Yamaha YZF-426 dirt bike. However, it not cheap at ~$250.

A Barnett clutch spring upgrade is available for the R1. If this kit is purchased, it should be noted that the stock clutch has only a single diaphragm spring which is discarded along with the pressure plate. The Barnett kit contains two sets of springs; silver (the stiffest) and gold (stiffer than the diaphragm spring but less stiff than the silver springs) with instructions to replace the diaphragm spring with gold (for street use) or silver (for racing) or a combination (for hard street use). Keep in mind that the OEM clutch is mechanically operated so stouter springs would make for sore hands on a motorcycle, but in a car application where the hydraulic conversion is used, the stiffest springs are probably your best bet (actually even if you stay mechanical). Our clutch demands in the car application are higher than any street bike can demand. The Barnett springs can be mixed (three silver and three gold) and the hold-down screws along with their individual spacers to match. The silver spacers (an insert into the inner coil of the spring) have been "turned" so they will go inside the thicker wire windings of the silver springs. Read the instructions. Lee Stohr reports that with the stiffer silver springs, pedal effort is normal.

R1 throttle bodies for marine applications with electronic fuel injection

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Factory Service Manuals in .pdf format                      

'98-'99 Manual
418 pages (14.6MB file!)

2000 Supplementary Manual
70 pages (1.4MB file)

2002 Manual broken into smaller chapter files for easier download

  • Chapter 0-1 (1.0MB file) Intro, Table of Contents, General Info.

  • Chapter 2     (2.6MB file) Specifications

  • Chapter 3     (2.9MB file) Periodic Checks & Adjustments

  • Chapter 4     (3.1MB file) Chassis

  • Chapter 5     (4.4MB file) Engine

  • Chapter 6-7 (1.4MB file) Cooling System, Fuel Injection System

  • Chapter 8-9 (1.8MB file) Electrical System, Troubleshooting, & Wiring Diagrams

Simplified "car" wiring diagram  (66KB file)
The wiring diagram was provided by Eric Liebscher

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