How To Install a Clutch Kit on a 1977 Yamaha IT250 Dirt Bike

How To Install a Clutch Kit on a 1977 Yamaha IT250

The 1977 Yamaha IT250 is a classic 250cc two-stroke trail/enduro machine that uses a cable-operated, wet multiplate clutch. Replacing the clutch kit on this bike restores throttle response, power transfer and crisp shifting after symptoms such as slipping under load, dragging between shifts, inconsistent lever feel or hard engagement. Below is a practical, rider-focused walkthrough suitable for basic to intermediate mechanics.

Why replace the clutch?

• Slipping under acceleration or when climbing indicates worn friction plates or weak springs.
• Dragging, where gears resist engagement, can come from warped steels, glazed friction material or contaminated oil.
• Inconsistent lever feel or excessive free play may be cable stretch or worn plates interacting with the basket notches.
• Hard shifting often results from plate thickness variation, bent pressure plate or spring imbalance.

Prepare the bike

• Park on a level surface and secure the bike on a stand so the rear wheel is off the ground.
• Clean around the clutch cover to prevent dirt entering the case when opened.
• Drain engine oil if your clutch cover shares the crankcase oil this bike uses a wet clutch, so plan to change or top up oil after the job.
• Disconnect the clutch cable at the lever and free it from any guides to create slack.

Remove the clutch cover and outer components

• Loosen and remove the clutch cover bolts in a crisscross pattern to ease the cover off. Keep bolts organized for reassembly.
• Note the orientation of any gaskets or Orings replace if damaged.
• Remove the pressure plate retaining springs and bolts gradually and evenly to release preload without cocking the plate.

Take out plates and inspect

Pull friction plates and steel drive plates out in sequence and stack them in order so you know the original arrangement. With the plates removed, inspect these parts:

• Friction plates - look for glazing, uneven wear, missing material or oil contamination. Slight glazing can be cleaned, but heavily worn or thin linings mean replacement.
• Steel plates - check for blueing or heat discoloration and feel for warping by laying on a flat surface; replace if obviously warped or deeply scored.
• Clutch basket - inspect the basket fingers for notching or grooves where plates engage. Notching will cause grabby engagement and may require filing or replacement.
• Inner hub splines - check for rounded splines or excessive play where plates ride; damaged splines cause clutch slip under load.
• Pressure plate and springs - confirm springs have even free length and no corrosion. Replace springs if they look weak or inconsistent; weak springs lower clamp force and cause slip.
• Thrust washer and pushrod (if present) - inspect for wear, flatness and smooth travel. A sticky or worn pushrod mimics plate problems.

Assess and decide

If the clutch basket or hub shows significant notching or spline wear, you'll want to address those parts along with the new kit to avoid rapid rewear of replacement plates. On smaller or lightly notched baskets, new plates can often restore proper function while you monitor for repeat wear.

Prepare new plates

• Soak new friction plates in fresh engine oil for at least 15-30 minutes so the clutch engages smoothly from first use.
• Wipe new steel plates clean and check each for flatness and consistent edge condition before assembly.

Reinstall the clutch pack

Install plates in the correct alternating order - friction, steel, friction - matching the sequence you removed them in. Ensure each plate seats fully in the basket and on the hub. Take care that any tabs or locating features engage their slots correctly so plates do not rotate independently.

Reassemble pressure plate and springs

• Compress the pressure plate evenly and install springs/bolts gradually in a cross pattern so the plate stays parallel to the hub.
• Tighten spring bolts snugly by hand, then bring them up in stages to even tension. Do not overtighten beyond handlevel confidence (consult your feel rather than exact specs).
• Check that the clutch lever and inner mechanism allow the plate to move freely when the lever is pulled.

Clutch cable adjustment & checks

Because the 1977 IT250 uses a cable clutch, adjust free play at the lever after reassembly. Typical play is a small amount at the lever tip before resistance - not so tight the clutch drags, not so loose it slips immediately. Inspect the cable for fraying, kinks or binding in the routing and lubricate if needed. Cable stretch can mimic worn plates, so set correct free play and retest before finalizing.

Final assembly and oil

• Reinstall clutch cover with a new gasket or properly seated Oring. Tighten cover bolts evenly.
• Refill engine oil to the recommended level with the correct viscosity for a wet clutch environment; clean oil improves clutch life and reduces glazing.
• Reconnect and adjust the clutch cable, then run the engine briefly to check engagement behavior and look for any leaks around the cover or cable area.

Test ride and breakin

On a short test ride, use varied loads and shifts to confirm the clutch grabs cleanly, releases smoothly and shifts crisply. Fresh plates often need a gentle breakin period with moderate acceleration and clutch use to seat evenly. If you still notice slippage, grabbing or unusual noises, recheck basket/hub wear and spring condition before assuming the new kit is at fault.

Context for IT250 riders

This 250cc trail/enduro machine experiences clutch wear from aggressive hill starts, tight woods sections that require frequent slipping and high heat in extended hard riding. Using correct, clean oil and checking cable routing regularly will prolong clutch life and keep the IT250 performing with the precise engagement you expect on trails.

Related Shopping Categories

Shop Clutch Kits for a 1977 Yamaha IT250 Dirt Bike.

Shop Clutch Baskets for a 1977 Yamaha IT250 Dirt Bike.

Shop Clutch Springs for a 1977 Yamaha IT250 Dirt Bike.

Shop Inner Hubs and Pressure Plates for a 1977 Yamaha IT250 Dirt Bike.

Shop Clutch Covers for a 1977 Yamaha IT250 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.