How To Install a Clutch Kit on a 2010 Yamaha YZ85 Dirt Bike

How To Install a Clutch Kit on a 2010 Yamaha YZ85

Why replace the clutch on a 2010 Yamaha YZ85

The 2010 Yamaha YZ85 is a youth motocross twostroke with a cableoperated, wet multiplate clutch. Typical symptoms that mean it's time for a clutch kit include slipping under aggressive launches, dragging or poor disengagement, inconsistent lever feel, hard or jerky shifts, and an overall loss of throttle response. Because this bike sees hard starts, sand, tight woods and heat, the friction plates and springs wear faster than on larger trail bikes replacing the clutch restores crisp power transfer and improves shift quality.

Tools & supplies you'll need

• Clutch kit matched to 2010 Yamaha YZ85 (friction plates, steels, springs)
• Basic metric hand tools & sockets
• Clutch holding tool or strap to prevent rotation
• Clean drain pan, shop rags and a toothbrush or soft brush
• Recommended engine oil for the YZ85
• Container with fresh oil for soaking plates
• Feeler gauge or simple ruler to check spring free length
• New clutch cover gasket or sealant as preferred

Preparing the bike

Park the YZ85 on a stand on level ground and let it cool. Remove the seat and any plastics blocking access to the clutch cover. Because this is a wet clutch, draining all the crankcase oil isn't strictly necessary for plate access, but removing some oil or placing a drain pan under the cover reduces mess if you'll open the clutch cover. Disconnect the clutch cable at the lever to give slack for cover removal.

Removing the clutch cover

Clean the area around the clutch cover to keep debris out of the engine. Loosen and remove cover bolts in a crisscross pattern. Gently pry the cover free it may stick if a gasket or sealant is used. Watch for oil; tilt the bike slightly if needed to control spillage. Remove the clutch cover and set it on a clean rag.

Disassembling the clutch

• Note the clutch stack orientation before removal take photos if helpful.
• Loosen the clutch spring bolts evenly a few turns at a time to avoid warping the pressure plate. Remove springs and pressure plate and set them aside in order.
• Slide out the friction plates and steel drive plates one by one, keeping the order if you want to compare wear patterns. On the YZ85 you'll see alternating friction and steel plates riding inside the clutch basket.
• Remove the inner hub if required to fully inspect splines and thrust surfaces.

Inspection checklist what to look for

• Friction plates look for glazing, excessive thinning, burnt smell, or uneven wear. Light surface glazing can sometimes be cleaned, but deep wear means replacement.
• Steel plates hold each plate on a flat surface and rock to check for warping; heavy discoloration or hot spots indicate replacement.
• Clutch basket inspect the basket fingers for notching or grooves where plate tabs ride. Moderate notching can be smoothed with careful filing; deep notches will cause drag and require basket replacement.
• Inner hub splines check for hooked or rounded splines that cause slippage or poor engagement.
• Clutch springs compare free lengths across all springs. If springs are significantly shorter or weak, replace them; uneven springs cause inconsistent pressure.
• Thrust washer & pushrod verify the pushrod moves smoothly and any thrust washers are not scored excessively.
• Oil condition dark, burnt oil accelerates clutch wear. Note oil smell and debris; change oil if it's degraded before reassembly.

Preparing new plates

Because the YZ85 uses a wet clutch, soak new friction plates in fresh engine oil for at least 10-15 minutes so they're fully saturated. This prevents initial dry slipping and aids proper engagement. Steel plates don't require soaking but wipe them clean of any surface rust or scale.

Reassembling the clutch

Reinstall plates in the exact alternating order friction plate, steel plate, friction, steel ending with the pressure plate configuration the original had. Make sure each plate seats correctly into the basket and hub splines. If you removed the inner hub, reinstall and ensure splines align cleanly without forcing plates.

Install the clutch springs and pressure plate, tightening spring bolts evenly in stages so the pressure plate compresses uniformly. Avoid overtightening; snug them until spring seats are even. Reconnect the clutch cable to the clutch arm but leave free play adjustment until after a test fit.

Clutch cover & oil

Clean mating surfaces and fit a new gasket or apply appropriate sealant. Reinstall the clutch cover and tighten bolts evenly. Refill or top off engine oil to the correct level for the YZ85 use the oil you trust for twostroke wet clutch performance. Proper oil viscosity and condition are important for clutch life.

Cable adjustment & hydraulic notes

Since the 2010 YZ85 uses a cableoperated clutch, set free play at the lever per a comfortable baseline a small amount of free play prevents constant slight drag while allowing full disengagement. Check the cable for smooth movement; if the cable is frayed, sticky, or binds, replace it because cable issues can mimic worn plates. Lubricate the cable if it feels stiff.

For riders transitioning to hydraulic clutches on other bikes hydraulic systems need consistent lever feel and leak inspection, and air will soften engagement but the YZ85's cable setup is simpler to service trackside.

Breakin and test riding

After reassembly and a careful leak check, warm the engine to operating temperature and work the clutch gently through the gears in a controlled area. Expect slightly different lever feel until plates bed in; avoid full throttle launches for the first few tanks to allow mating surfaces to settle. Properly installed, the new clutch will restore immediate throttle response, positive power transfer, and smoother shifts especially noticeable on the smalldisplacement, highrevving YZ85 used for motocross starts and technical riding.

Final inspection tips

• Recheck clutch cable free play after the first ride and adjust as needed.
• Listen for unusual noises or dragging between shifts these hint at installation issues or basket damage.
• Keep a maintenance log of oil changes and riding conditions; sand, frequent launches and hot climates accelerate clutch wear on the 85cc motocross platform.

Related Shopping Categories

Shop Clutch Kits for a 2010 Yamaha YZ85 Dirt Bike.

Shop Clutch Baskets for a 2010 Yamaha YZ85 Dirt Bike.

Shop Clutch Springs for a 2010 Yamaha YZ85 Dirt Bike.

Shop Inner Hubs and Pressure Plates for a 2010 Yamaha YZ85 Dirt Bike.

Shop Clutch Covers for a 2010 Yamaha YZ85 Dirt Bike.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.