2017 Yamaha YZ85O

There isn’t a specific Yamaha model called the “YZ850” in that year, therefore I think you might be referring to the YZ450F from that year. Yamaha’s well-known motocross motorcycle, the YZ450F, was updated for the 2017 model year. The 2017 Yamaha YZ450F is introduced in the following manner:

2017 Yamaha YZ450F model
The 2017 Yamaha YZ450F is a high-performance motocross motorbike built for enthusiasts and competitors who seek the best handling and performance on dirt tracks. It is a member of Yamaha’s YZ series, which has a long history of creating off-road motorcycles that have won championships.

Key characteristics

• 449cc Liquid-Cooled 4-Stroke Engine: The YZ450F is propelled by a 449cc, four-stroke, single-cylinder engine with liquid cooling. It is well suited for motocross racing since it produces powerful and consistent power across the rpm range.
• Electronic fuel injection (EFI) on the motorcycle ensures precise fuel distribution and optimum engine performance under a variety of riding circumstances.
• Aluminum Frame: Yamaha built the YZ450F with a lightweight yet durable aluminum frame to increase the bike’s agility and stability.
• High-quality KYB suspension parts are used, including a front fork and rear shock that are fully adjustable. This enables riders to fine-tune the suspension to their preferences and adapt to various track conditions.
• Electric Start: The 2017 YZ450F has an electric start feature that makes it simpler to start the motorcycle, especially in difficult circumstances.
• For this model year, Yamaha debuted Launch Control, which aids riders in achieving the best traction and acceleration off the line. This function is especially useful in motocross competitions.
• Riders can select from a variety of engine maps to customize the power delivery to their preferences or the particular track circumstances.
• Advanced Braking: The motorcycle has strong disc brakes in the front and back that offer exceptional stopping force and control.
• Rider ergonomics were taken into consideration when designing the YZ450F, which features a comfortable seat, adjustable handlebars, and footpegs that can be adjusted to fit different riding styles and rider sizes.
• Race-Ready Design: The YZ450F boasts a distinctive look that reflects its racing heritage thanks to its aggressive styling and graphics.

Motocross aficionados and professional riders praised the 2017 Yamaha YZ450F for its handling, performance, and cutting-edge features. It remained a viable choice on the motocross racing scene. Please be aware that certain information may change depending on your location or any alterations the bike’s owner makes.

Instrument and control functions

Fuel

This motorcycle has been designed to use a premixed fuel of gasoline and 2-stroke engine oil. Always mix the gaso-line and oil in a clean container before filling the fuel tank.

NOTICE
Always use fresh gasoline, and fill the fuel tank with a fresh mix just be-fore riding. Do not use premixed fuel that is more than a few hours old.

Mixing gasoline and 2-stroke engine oil
Pour 2-stroke engine oil into a clean container, and then add gasoline. To mix the fuel thoroughly, shake the con-tainer from side to side.

1. 2-stroke engine oil
2. Gasoline
3. Container

Recommended fuel:
Premium unleaded gasoline (Gaso-hol [E10] acceptable) Recommended 2-stroke engine oil:
See page 9-1.
Fuel tank capacity:
5.0 L (1.3 US gal, 1.1 Imp.gal) Mixing ratios (gasoline to oil):
Break-in period:
15:1 After break-in: 30:1

NOTICE
Use only unleaded gasoline. The use of leaded gasoline will cause severe damage to internal engine parts, such as the piston rings as well as to the exhaust system. Your Yamaha engine has been de-signed to use premium unleaded gas-oline with a pump octane number [(R+M)/2] of 91 or higher, or a research octane number of 95 or higher. If knocking (or pinging) occurs, use a gasoline of a different brand.
If the recommended 2-stroke engine oil is not available, use an equivalent oil.

Gasohol
There are two types of gasohol: gaso-hol containing ethanol and that con-taining methanol. Gasohol containing ethanol can be used if ethanol content does not exceed 10% (E10). Gasohol containing methanol is not recom-mended by Yamaha because it can cause damage to the fuel system or vehicle performance problems.

NOTICE
Never mix two brands of 2-stroke engine oil in the same batch. Always use the same type of oil to ensure maximum engine performance. Should it be necessary to use a dif-ferent oil brand, be sure to drain the fuel tank and the carburetor float chamber of the old premixed fuel prior to filling with the new type.

Filling the fuel tank

1. Maximum fuel level
2. Fuel tank filler tube

WARNING
Gasoline and gasoline vapors are extremely flammable. To avoid fires and explosions and to reduce the risk of injury when refueling, follow these instructions.

1. Before refueling, turn off the en-gine and be sure that no one is sit-ting on the vehicle. Never refuel while smoking, or while in the vi-cinity of sparks, open flames, or other sources of ignition such as the pilot lights of water heaters and clothes dryers.
2. Do not overfill the fuel tank. Stop filling when the fuel reaches the bottom of the filler tube. Because fuel expands when it heats up, heat from the engine or the sun can cause fuel to spill out of the fuel tank.
3. Wipe up any spilled fuel immedi-ately. NOTICE: Immediately wipe off spilled fuel with a clean, dry, soft cloth, since fuel may deteriorate painted surfaces or plastic parts. [ECA10072]
4. Be sure to securely close the fuel tank cap.

WARNING
Gasoline is poisonous and can cau-se injury or death. Handle gasoline with care. Never siphon gasoline by mouth. If you should swallow some gasoline or inhale a lot of gasoline vapor, or get some gasoline in your eyes, see your doctor immediately. If gasoline spills on your skin, wash with soap and water. If gasoline spills on your clothing, change your clothes.

Adjusting the front fork

WARNING
Always adjust both fork legs equally, otherwise poor handling and loss of stability may result. This front fork is equipped with re-bound damping force adjusting screws and compression damping force ad-justing screws.

NOTICE
To avoid damaging the mechanism, do not attempt to turn beyond the maximum or minimum settings.

Rebound damping force
To increase the rebound damping for-ce and thereby harden the rebound damping, turn the adjusting screw on each fork leg in direction (a). To de-crease the rebound damping force and thereby soften the rebound damping, turn the adjusting screw on each fork leg in direction (b).

This shock absorber assembly con-tains highly pressurized nitrogen gas. Read and understand the fol-lowing information before handling the shock absorber assembly.

• Do not tamper with or attempt to open the cylinder assembly.
• Do not subject the shock ab-sorber assembly to an open flame or other high heat source. This may cause the unit to ex-plode due to excessive gas pressure.
• Do not deform or damage the cylinder in any way. Cylinder damage will result in poor damping performance.
• Do not dispose of a damaged or worn-out shock absorber as-sembly yourself. Take the shock absorber assembly to a Yamaha dealer for any service.
• Never apply force on the motor-cycle while it is on the side-stand.
• Always remove the sidestand before starting out.

Inspect your vehicle each time you use it to make sure the vehicle is in safe oper-ating condition. Always follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.

WARNING
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equipment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer.

Operation and important riding points

Starting a warm engine
Follow the same procedure as for starting a cold engine with the excep-tion that the starter (choke) is not re-quired when the engine is warm. Instead, start the engine with the throt-tle slightly open..

To start out and accelerate

1. Pull the clutch lever to disengage the clutch.
2. Shift the transmission into first gear.
3. Open the throttle gradually and si-multaneously release the clutch lever slowly.
4. Once the motorcycle has reached a speed high enough to change gears, close the throttle, and at the same time, quickly pull the clutch lever in.
5. Shift the transmission into second gear. (Make sure not to shift the transmission into the neutral posi-tion.)
6. Open the throttle halfway and gradually release the clutch lever.
7. Follow the same procedure when shifting to the next gear.

To decelerate

1. Close the throttle and apply both the front and the rear brakes to slow the motorcycle.
2. Downshift through the gears and shift the transmission into the neu-tral position when the motorcycle is almost completely stopped.

Engine break-in

1. Before starting the engine, fill the fuel tank with a break-in oil-fuel mixture as follows.
2. Start and warm up the engine. Check the operation of the con-trols and the engine stop switch.(See page 4-1.)
3. Operate the motorcycle in the low-er gears at moderate throttle openings for five to eight minutes. Stop the engine and check the spark plug condition (see page 7-6); it will show a rich condition during break-in.
4. Allow the engine to cool. Restart the engine and operate the motor-cycle as in the step above for five minutes. Then, very briefly shift to the higher gears and check the full-throttle response. Stop the en-gine and check the spark plug.
5. After again allowing the engine to cool, restart and run the motorcy-cle for five more minutes. Full throttle and the higher gears may be used, but sustained full-throttle operation should be avoided. Stop the engine and check the spark plug again.
6. Allow the engine to cool, remove the cylinder head and cylinder, and inspect the piston and cylin-der. Remove any high spots on the piston with #600-grit wet sandpaper. Clean all components and carefully reassemble the cyl-inder head and cylinder.
7. Drain the break-in oil-fuel mixture from the fuel tank and refill with the specified mix. (See page 4-4.)
8. Start the engine and check the op-eration of the motorcycle through-out its entire operating range. Stop the engine and check the spark plug condition. Restart the motorcycle and ride it for about 10 to 15 more minutes. The motorcy-cle will now be ready to ride nor-mally.

After the engine break-in period, thor-oughly check the motorcycle for loose parts, oil leakage and any other prob-lems. Be sure to inspect and make ad-justments thoroughly, especially cable and drive chain slack and loose spokes. In addition, check all fittings and fasteners for looseness, and tight-en if necessary.

FAQ