How To Install a Clutch Kit on a 1978 Suzuki RM100 Dirt Bike

How To Install a Clutch Kit on a 1978 Suzuki RM100

Why replace the clutch on a 1978 Suzuki RM100?

The 1978 Suzuki RM100 is a lightweight 100cc motocross bike built for quick revs and frequent clutch use. Over time a wet multiplate clutch will show wear symptoms include slipping under throttle, dragging when releasing the lever, inconsistent lever feel, hard shifts, or a spongy cable sensation. Aggressive starts, sand, woods riding and high heat accelerate wear. Replacing the clutch kit restores crisp power transfer, predictable engagement and better throttle response so the little RM delivers where it should.

Overview of the RM100 clutch system

The RM100 uses a cableoperated, wet multiplate clutch. Key parts you'll handle during replacement are the clutch cover, pressure plate, clutch springs, friction plates, steel drive plates, clutch hub, clutch basket and inner hub splines. Expect to work with a pushrod and thrust washer arrangement on disassembly and reassembly. Because it's cable driven, check the cable and lever while you're at it improper cable tension or a binding cable can mimic worn plates.

Preparation

• Park the bike on a level surface and secure it on a stand so the rear wheel is off the ground.
• Clean the clutch cover area to prevent dirt from entering the case when opened.
• Gather tools: metric sockets and wrenches, screwdrivers, clutch spring tool or appropriate wrench, drain pan, clean rags, fresh engine oil and a container to soak new plates.
• If you prefer, drain the engine oil into a pan many riders remove and replace plates without a full drain on small twostrokes, but draining reduces mess and ensures old oil doesn't contaminate new plates. Decide based on your comfort level.

Removing the clutch

• Loosen the clutch cable at the lever to create slack. This prevents spring tension while you remove the pressure plate.
• Remove the bolts securing the clutch cover. Carefully pry the cover loose; use a soft mallet or gentle lever if it's stuck, avoiding gouging the mating surfaces.
• With the cover removed you'll see the pressure plate and clutch springs. Loosen springs in a crisscross pattern several turns at a time to relieve pressure evenly.
• Remove springs and the pressure plate, then pull out the stack of friction and steel plates, noting the order. Lay plates out sequentially so you can confirm correct reassembly order.
• Remove any thrust washer and pushrod components for inspection remember how the pushrod interfaces with the diaphragm or pressure plate.

Inspection what to look for on the RM100

• Friction plates check for glazing, excessive thinning or burnt odor. Glazed plates feel smooth and shiny; they don't grab like fresh plates.
• Steel drive plates look for blueing or warping. Place on a flat surface; a warped plate will rock. Slight discoloration from heat is common but heavy warping means replacement.
• Clutch basket and hub inspect basket fingers for notching where the plates engage. Notched fingers cause grabbing and chatter. Check hub splines for burrs or wear where inner plate splines ride.
• Springs compress and compare free lengths sidebyside. Weak or uneven springs change engagement and should be swapped.
• Thrust washer and pushrod ensure the thrust faces are smooth and the pushrod moves freely without binding.
• Oil condition inspect for metallic debris; heavy contamination suggests additional engine wear. Use fresh twostroke compatible oil when refilling.

Preparing new plates

If you are installing a wet clutch kit, soak the new friction plates in the appropriate oil for at least 20-30 minutes before assembly so they're saturated and ready to grab. Stack them in a clean container partially submerged. Meanwhile wipe down the basket, hub and pressure plate mating surfaces with a clean rag do not use solvents that leave residues.

Reassembling the clutch

• Reinstall the pushrod and thrust washer exactly as removed.
• Fit plates in the original sequence typically starting with a friction plate against the clutch basket and alternating steel and friction plates until the stack is complete. Confirm the last plate type matches the original setup.
• Slide the pressure plate into place, ensuring the hub and basket alignment are correct and plates sit flush without binding.
• Install clutch springs and tighten evenly in a crisscross pattern until fully seated. Tighten gradually to avoid cocking the pressure plate.
• Before reinstalling the clutch cover, set the clutch cable free play roughly to the middle of its adjustment range so you can finetune later. Ensure the lever returns smoothly and the cable routes without sharp bends.
• Replace the clutch cover gasket if it was damaged, then fit the cover and tighten bolts progressively in a star pattern to seat it evenly.

Finishing steps and checks

• If you drained oil, refill with the correct type and quantity for the RM100 twostroke. If you didn't drain, top up if needed and run the engine briefly to circulate oil through new plates.
• Adjust cable free play at the lever to a light amount of slack per rider preference enough to fully disengage the clutch without excess travel. Check that engagement feels firm and consistent.
• Start the bike and test clutch engagement at low RPMs in neutral, then ride gently to bed in plates avoid full throttle launches for the first few miles. Recheck lever feel and cover bolts after an initial ride.

Why proper installation matters

A properly installed clutch kit returns your 1978 Suzuki RM100 to its intended behavior clean shifts, reliable launches and better overall control on motocross tracks or trails. Replacing worn plates and springs eliminates slipping, reduces heat buildup and stops inconsistent lever response. Taking time to inspect the basket, hub and cable ensures the repair lasts and protects the rest of the drivetrain.

Related Shopping Categories

Shop Clutch Kits for a 1978 Suzuki RM100 Dirt Bike.

Shop Clutch Baskets for a 1978 Suzuki RM100 Dirt Bike.

Shop Clutch Springs for a 1978 Suzuki RM100 Dirt Bike.

Shop Inner Hubs and Pressure Plates for a 1978 Suzuki RM100 Dirt Bike.

Shop Clutch Covers for a 1978 Suzuki RM100 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.