MOTO-MASTER Ultralight Steel Rear Sprocket for SUZUKI RM 80, RM 85, KAWASAKI KX 80, KX 85 and YAMAHA YZ 80, YZ 85 1982-2026

The MOTO-MASTER steel rear sprocket is designed for YAMAHA YZ 80, YZ 85, KAWASAKI KX 80, KX 85 and SUZUKI RM 80, RM 85 from 1982 to 2026. The rear sprocket is the large sprocket bolted to the rear wheel hub: together with the front sprocket and the chain, it transmits the engine's power to the wheel. Made of steel, it stands up to wear far better than an aluminium sprocket, especially in mud and sand.

Specifications

• Brand: MOTO-MASTER
• Manufacturer part numbers: 620041146, 620041147, 620041148, 620041149, 620041150, 620041151, 620041152, 620041153
• Chain pitch: 428
• Material: steel
• Available versions: 46 Teeth: ref. 620041146; 47 Teeth: ref. 620041147; 48 Teeth: ref. 620041148; 49 Teeth: ref. 620041149; 50 Teeth: ref. 620041150; 51 Teeth: ref. 620041151; 52 Teeth: ref. 620041152; 53 Teeth: ref. 620041153
• Weight: 600 g
• Engine: 2-stroke

Choosing the right number of teeth

For the same bike, go for the number of teeth of your current sprocket (it's often stamped on it). More teeth on the rear sprocket shortens the gearing: more acceleration, lower top speed. Fewer teeth lengthens it. Even one or two teeth make a clear difference; if you change a lot, the chain length may need adjusting.

When to replace it?

• Teeth worn to a point or into a hook shape, worn down on one side only.
• Chain that lifts away from the sprocket when you pull it rearwards.
• Drivetrain noise, jerkiness or a chain that jumps under load.

Check the sprocket every time you service the chain. Always replace the rear sprocket, front sprocket and chain together: a new part running with worn ones wears out very quickly.

Fitting tips

1. Clean the hub and check that it isn't cracked or distorted.
2. Fit the sprocket the right way round (markings facing out) and tighten the bolts in a criss-cross pattern to the manufacturer's torque, with medium-strength threadlocker if the manual calls for it.
3. While you're at it, replace the front sprocket and the chain if they're worn.
4. Set the chain tension as per the manual, with the wheel aligned, then lube it with a suitable chain lube.
5. Recheck the bolt tightness and the chain tension after the first ride.

Why MOTO-MASTER?

In motocross, Moto-Master was working with the Red Bull KTM Factory Racing team as early as 2010, and it backed the MXGP world championship in 2015. On the technical side, the Flame profile of its discs is designed to improve cooling and go easy on the pads, and its Racing GP sintered pads use a backing plate with hooks (NRS technology) that stops the friction material from coming away.

Spare parts and items to plan

• Front sprocket : PBR 560 1 · PBR 416 1
• Drive chain : AFAM A420MX2-G · AFAM A428MX-G 1
• Chain lube : LIQUI MOLY 400 ml · MUC OFF 400 ml

Frequently asked questions

Aluminium or steel?
Aluminium is lighter and works well for motocross and racing. Steel lasts longer: it's the best choice for enduro, sandy terrain or if you put in a lot of hours.

Should the chain be replaced at the same time?
Yes, if it's worn: a stretched chain wears out a new sprocket in a few hours.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
KAWASAKI KX 80 2000
KAWASAKI KX 80 1999
KAWASAKI KX 80 1998
KAWASAKI KX 80 1997
KAWASAKI KX 80 1996
KAWASAKI KX 80 1995
KAWASAKI KX 80 1994
KAWASAKI KX 80 1993
KAWASAKI KX 80 1992
KAWASAKI KX 80 1991
KAWASAKI KX 80 1990
KAWASAKI KX 80 1989
KAWASAKI KX 80 1988
KAWASAKI KX 80 1987
KAWASAKI KX 80 1986
KAWASAKI KX 85 2025
KAWASAKI KX 85 2024
KAWASAKI KX 85 2023
KAWASAKI KX 85 2022
KAWASAKI KX 85 2021
KAWASAKI KX 85 2020
KAWASAKI KX 85 2019
KAWASAKI KX 85 2018
KAWASAKI KX 85 2017
KAWASAKI KX 85 2016
KAWASAKI KX 85 2015
KAWASAKI KX 85 2014
KAWASAKI KX 85 2013
KAWASAKI KX 85 2012
KAWASAKI KX 85 2011
KAWASAKI KX 85 2010
KAWASAKI KX 85 2009
KAWASAKI KX 85 2008
KAWASAKI KX 85 2007
KAWASAKI KX 85 2006
KAWASAKI KX 85 2005
KAWASAKI KX 85 2004
KAWASAKI KX 85 2003
KAWASAKI KX 85 2002
KAWASAKI KX 85 2001
KAWASAKI KX 85 2000
SUZUKI RM 80 2001
SUZUKI RM 80 2000
SUZUKI RM 80 1999
SUZUKI RM 80 1998
SUZUKI RM 80 1997
SUZUKI RM 80 1996
SUZUKI RM 80 1995
SUZUKI RM 80 1994
SUZUKI RM 80 1993
SUZUKI RM 80 1992
SUZUKI RM 80 1991
SUZUKI RM 80 1990
SUZUKI RM 80 1989
SUZUKI RM 80 1988
SUZUKI RM 80 1987
SUZUKI RM 80 1986
SUZUKI RM 80 1985
SUZUKI RM 80 1984
SUZUKI RM 80 1983
SUZUKI RM 80 1982
SUZUKI RM 85 2026
SUZUKI RM 85 2025
SUZUKI RM 85 2024
SUZUKI RM 85 2023
SUZUKI RM 85 2022
SUZUKI RM 85 2021
SUZUKI RM 85 2020
SUZUKI RM 85 2019
SUZUKI RM 85 2018
SUZUKI RM 85 2017
SUZUKI RM 85 2016
SUZUKI RM 85 2015
SUZUKI RM 85 2014
SUZUKI RM 85 2013
SUZUKI RM 85 2012
SUZUKI RM 85 2011
SUZUKI RM 85 2010
SUZUKI RM 85 2009
SUZUKI RM 85 2008
SUZUKI RM 85 2007
SUZUKI RM 85 2006
SUZUKI RM 85 2005
SUZUKI RM 85 2004
SUZUKI RM 85 2003
SUZUKI RM 85 2002
YAMAHA YZ 80 2001
YAMAHA YZ 80 2000
YAMAHA YZ 80 1999
YAMAHA YZ 80 1998
YAMAHA YZ 80 1997
YAMAHA YZ 80 1996
YAMAHA YZ 80 1995
YAMAHA YZ 80 1994
YAMAHA YZ 80 1993
YAMAHA YZ 85 2026
YAMAHA YZ 85 2025
YAMAHA YZ 85 2024
YAMAHA YZ 85 2023
YAMAHA YZ 85 2022
YAMAHA YZ 85 2021
YAMAHA YZ 85 2020
YAMAHA YZ 85 2019
YAMAHA YZ 85 2018
YAMAHA YZ 85 2017
YAMAHA YZ 85 2016
YAMAHA YZ 85 2015
YAMAHA YZ 85 2014
YAMAHA YZ 85 2013
YAMAHA YZ 85 2012
YAMAHA YZ 85 2011
YAMAHA YZ 85 2010
YAMAHA YZ 85 2009
YAMAHA YZ 85 2008
YAMAHA YZ 85 2007
YAMAHA YZ 85 2006
YAMAHA YZ 85 2005
YAMAHA YZ 85 2004
YAMAHA YZ 85 2003
YAMAHA YZ 85 2002