Fix a slipping clutch
Changing plates needn’t be a dealer job with these top tips
Familiarise yourself 1
If your clutch has started to slip you’ll need to check or replace the plates. The majority of Japanese bikes have a wet clutch; where the friction plates are bathed in engine oil. Typically, the clutch is under an engine casing with a water pump integrated into it. There are usually no special tools required, all you will need is a new set of clutch plates and a fresh cover gasket.
Drain the fluids 2
Undo the clutch actuating lever if fitted and then remove the clutch cable. The bike pictured has a pushrod layout housed on the opposite side and this can remain in place when the clutch plates are changed. Undo the bolts that retain the clutch cover. As you do, it’s worth making a note of their length and where each one is located.
Spin out the bolts 3
If necessary drain the coolant from the engine by removing the drain bolt. Next drain the oil from the engine in to a suitable container, when the oil has drained replace the sump bolt and torque it up to the value in the manual. If the bike’s on a main or paddock stand, place it onto its sidestand to prevent any residual oil spilling out once the clutch cover is removed.
Gently remove the cover 4
With all of the cover bolts removed, do a final check to make sure that there aren’t any hidden ones left. Then gently pull the cover off, keeping an eye out for any locating dowels which may drop out. If the cover refuses to budge, have look around the edges for pry points. Use these carefully so that you don’t cause any damage.
Pull off the plates 5
The clutch pressure plate is retained by four to six bolts that tighten inside springs. Undo these and remove them, the pressure plate should then be free. Remove plates individually, making a note of the order. There will usually be a friction plate followed by a steel plate, and so on.
Clean and inspect 6
Clean the clutch drum and basket with brake cleaner. Use a brush to agitate deposits then blast with another squirt of brake cleaner. Do the same on both sides of the pressure plate and clutch cover casing. Remove all traces of the old gasket and use a Scotchbrite pad to scrub off stubborn bits.
Soak the new plates 7
New friction plates need to be soaked in the same grade and type of oil used in the engine or gearbox. The steel plates need to be covered in a thin film of oil, too. Leave the friction plates to soak in the oil for an hour or so, then fit the dowels into the engine side and put the new cover gasket carefully in place.
Fit new plates 8
Refit the new plates in the correct sequence: friction first, then steel. Be sure to fit the steel plates the right way around, usually with the round edges facing the clutch basket. Now refit the pressure plate, sometimes there are marks to locate it correctly as it lines up with the clutch basket. Refit the springs, tighten them up evenly at first then torque them up to spec.
Check and cover 9
If your clutch is operated by an internal pushrod you can check the action by squeezing the handlebar lever. When pulled in the clutch plates should separate by a few mm, then get compressed by the pressure plate when the lever is out. Re-fit the clutch cover, lining up any water pump drive gears etc, and then lightly tighten up the cover bolts before torquing up.
Refill the oil 10
Check the sump plug is torqued-up properly, then measure out the gearbox or engine oil and fill up to the correct level. Start the engine for a few minutes then stop it and re-check the oil level. Before you take the bike for a test ride you need to check the clutch lever free-play, it is likely that this has changed so make any necessary adjustment.