Fix your clutch
How to change plates
1 Understand the plan
The clutch smoothly transmits the power from the crankshaft via the primary and secondary gears to the gearbox. But the friction plates can start to wear. Symptoms can be slipping under acceleration, and/or grabby feel. On a lot of bikes these plates can be changed quite easily. Try to source a workshop manual and have all your tools laid out before you start.
2 A draining experience
On most bikes the clutch is on the right-hand side of the engine, and the Yamaha engine shown in this picture is typical of most layouts. In this case we need to drain both the engine oil and coolant as the right-hand cover also houses the water pump. First of all remove the sump bolt and let all of the oil drain away into a suitable tray.
3 Remove hoses and cables
Drain the coolant and remove any water hoses going to the clutch cover casing. On our Yamaha we also needed to disconnect the oil pump, so there was a cable to remove, as well as an oil-in pipe and an oil-out pipe. The clutch cable is then disconnected. On this engine it is on the other side of the crankcase, and the movement is transmitted via a pushrod.
4 Remove cover carefully
Evenly undo the bolts or screws that retain the clutch cover, remove them and lay them out in a sequence that helps when refitting. Gently remove the clutch cover. Occasionally they can be stubborn, so check all bolts are removed. Sometimes there are pry points, use these carefully to avoid damaging the cases.
6 Put new plates in place
Clean the empty clutch drum and basket, then soak the new friction plates in oil. Steel plates just need to be smeared with oil. Install the plates, in the correct sequence – usually friction, steel, friction. Make sure the steel plates go in with the round edge facing the engine. Replace the pressure plate, fit new springs and tighten up.
8 Get everything in line
With a new gasket fitted, offer the cover up and gently place it against the engine. There are usually several things that all need to line up simultaneously for the cover to go on. On this Yamaha there are two dowel pins that need to line up, as well as the oil pump and water pump drive gears. When it all lines up there is usually a clunk as it sits squarely on the gasket surface.
5 Rate your plates
The clutch pressure plate is retained by four to six bolts that tighten inside springs. Remove these and pull the clutch top off. Remove the plates and inspect them. Your bike’s manual will say how thick a friction plate should be, so measure them. Worn steels become discoloured, blue and scorched.
7 Clean up your act
When the clutch cover is removed the gasket often gets damaged. This needs to be scraped off and cleaned back to a bare surface. You can very gently pick or scrape the remains of a gasket off with a blade; don’t be tempted to dig in too hard. Any stubborn bits can be lightly abraided off with a scotchbrite pad.
9 Finishing touches
Install the bolts that secure the cover, making sure that the different length bolts go into the correct holes. Tighten them all up evenly, then tighten up to the correct spec. Fill the engine up to the correct level with oil. Reconnect anything that was removed. Finally check the clutch lever freeplay, and adjust to spec. Test ride the bike carefully and check for leaks.