Yamaha · 2026
YZ85
The YZ85 is the long-running 85cc two-stroke that bridges the 65cc minis and the full-size 125 class. Yamaha pairs the liquid-cooled motor with the YPVS power valve for a broader, more usable spread of power, which makes it a forgiving step up for riders moving off a 65. A big-wheel "LW" variant runs larger wheels for taller riders.
Engine & specifications
- Displacement
- 85cc
- Bore × stroke
- 47.5 × 47.8 mm
- Cooling
- Liquid-cooled
- Induction
- reed-valve inducted
- Power valve
- YPVS (Yamaha Power Valve System)
- Starter
- Kick
- MSRP (new)
- Not yet documented
Transmission
- Gears
- 6-speed
- Clutch
- Not yet documented
- Final drive
- Chain
Suspension
- Front
- 36mm KYB inverted cartridge fork, fully adjustable
- Front travel
- 10.8 in
- Rear
- KYB link-type shock, fully adjustable
- Rear travel
- 11.1 in
Brakes
- Front
- 220mm
- Rear
- 190mm
- Type
- Wave-style hydraulic discs
Wheels & tires
- Front rim
- 17"
- Rear rim
- 14"
- Front tire
- Dunlop MX3S
- Rear tire
- Dunlop MX3S
Dimensions & fuel
- Seat height
- 33.1 in
- Wheelbase
- 49.4 in
- Ground clearance
- 12.6 in
- Weight
- 161 lb (Wet weight)
- Fuel
- 1.3 gal
- Premix ratio
- Not yet documented
Fluids
Not yet documented from the service manual for this year.
Fluid types and capacities vary by year and model — we publish them only from the service/owner's manual. Always confirm against your manual before service.
Torque & spec reference
Not yet documented from the service manual for this year.
Torque values can strip threads or fail a component if wrong — we list them only as published in the service manual for this exact year-model. When in doubt, use your manual and a calibrated torque wrench.
Known issues
No verified year-specific issues documented yet.
Common upgrades
- ▸Fresh top-end on schedule — 85cc two-strokes wear pistons/rings fast under race use.
- ▸Aftermarket pipe + silencer to tune the powerband for a rider’s pace.
- ▸Grip/lever and sprocket (gearing) changes to match track and rider size.
Parts compatibility
A big-wheel "LW" version uses larger wheels/tires than the standard YZ85; confirm standard vs LW before ordering wheels, tubes, or tires.
Manual links
We haven’t linked a verified manual for this year yet. Always service to your model-year owner’s/service manual.
Owner tips
- ▸Run fresh premix at the manufacturer’s ratio — confirm the exact ratio in the manual.
- ▸Clean and re-oil the air filter basically every ride; grit is what kills mini two-strokes.
Maintenance checklist
Do this basically every ride. A clogged filter chokes power; a torn one lets grit into the engine.
A two-stroke’s gearbox runs on its own oil — clean trans oil keeps shifting and the clutch crisp.
The piston and rings wear out. Replacing on time prevents a far more expensive bottom-end failure. (2-strokes need it much sooner than 4-strokes — check your manual.)
A worn chain and sprockets rob power and can snap. Replace as a set.
Fresh coolant stops overheating and corrosion. Roughly once a season for most riders.
Re-greasing the suspension linkage and wheel bearings keeps the bike handling right and saves bearings.
Guideline intervals only — they vary by year and how hard the bike is ridden. Always confirm exact figures in your owner's manual.
Aftermarket parts
Each link opens an Amazon search for this model. MWR earns a small commission at no extra cost to you.
Used buying guide
On a used 85 two-stroke, ask for top-end hours and look for fresh, even piston wear. Check the powervalve is clean and moving, the clutch isn’t slipping, and the suspension isn’t leaking. Minis lead hard lives — service history matters more than cosmetics.
Sources
- Yamaha Motorsports — 2026 YZ85 specifications — verified 2026-06-19
Blank fields are values we haven’t verified for this exact year-model yet — we leave them blank rather than guess. Torque and fluid specs are published only from the service manual. Always follow your owner’s manual for service.