Bike Setup Yamaha YZ125/250 2 Stroke

Make:  Yamaha

Model: YZ125 YZ250 2Stroke

Relevant Years: 2016-2023

Oem Trim / Test notes:  A well balanced bike in standard trim.  We find the shock action quite loose and firm for most riders across all the year models.  The forks generally are on the firm side especially for junior racers and all riders aboard the 2021 + models.  These 2021+ bikes are much firmer than all the previous year bikes suiting bigger riders on wide open tracks.    With these new models we are using our Mid Post assembly to add plushness resulting in a much-improved fork action and feel.  For 2022 this modification alone transforms these 2 strokes resulting in a much easier ride with less chatter and arm pump.   A new setting in the rear shock will match up and finish the setup for improved action on rough tracks.



Base Setup – Disassemble clean and inspect suspension units.  Modify Valving specs to Krooztune tested data.  Install service parts required and rebuild suspension units to specification.

Fork only $450

Shock only $350  

Fork and Shock $800

Lowering Options Available, call for information



If rider weight is outside of oem spring rate range, heavier or lighter fork and shock springs may be required.

Fork $219.95

Shock $219.95

*Service wear parts and performance upgrade parts not included   


Additional Service Options

Chassis service / regrease pivot points.  Head stem, Linkage, swingarm. Labour and grease $150

*Wear parts not included


Optional Krooz Racing Performance parts:


Highspeed Compression piston – High flow Alloy piston to reduce highspeed shaft induced compression spikes.

Performance Linkage- Allows rear end hold down and a flatter bike into the turns without the need to reduce shock spring preload.   Retaining excellent drive out of the turns and reducing sudden weight transfer under heavy braking scenarios.  (Not always required on these 2 Strokes, although very good when used in the sand or fast highspeed tracks)


Mid Valve Post Assembly – The oem mid valve compression and rebound post we have tested to be best suited for pro and high A level riders only.  Our Krooz Racing Midvalve post assembly allows a much plusher feeling in hand and a smoother overall suspension action better suited to most Aus MX applications and harsh conditions.  This mod is a must do for 2021 model on 2 stroke machines.


Common Service parts

SKF Heavy Duty Forkseals $100

Shock Sealhead rebuild kit $50

Fork Bushes x2 $40 (most common) or x4 bushes in kit $80


Further Performance Suspension Upgrade Options

Xtrig Preload adjuster $280

DLC Black fork tubes $450 each (2 required)

Kashima Upper tubes $550 each (2 required)


Technical Touch Factory Kit Option

Fork  $5500

Shock $3700

Xtrig Clamps $1150 including PHDS bar mounts


Steering Damper

Precision Steering Damper available $1100