Just about to overtake and despatch a slow Sunday driver, you pull out, road clear, give the throttle a good twist and leave them for dust. But no – Grrrr! Clutch slip! The rev counter flies round, the engine screams for mercy, but you’re not going anywhere – eh?! Seconds later the clutch finally grips and wham! forward you finally shoot. A worn clutch slipping has to be one of the most infuriating issues to put up with.
My FZS600 had hit 50k and mostly slow speed work in the city, so I can’t moan too much about it finally giving up. I had already replaced the clutch cable a couple of years ago and re-checked adjustment, so concluded it was probably time for new clutch plates. I picked up a set of new EBC friction clutch plates and heavy duty springs, as consensus suggested both should be changed together (and a spring set is only a tenner). And not forgetting I also grabbed a new clutch cover gasket too.
Swapping clutch plates is a fairly straight job and described well by Ashley Debell in this FZS Clutch Replacement YouTube vid. Do soak your new plates in oil for a few hours prior. Do ensure the clutch pressure plate is in the correct position before tightening up the spring bolts – it only sits flush in one position. Do use a torque wrench, as only minimal torque is required (8Nm for springs bolts, 12Nm clutch cover bolts). I gave my bike an oil change at the same time, but the clutch can be serviced with oil in-situ with no oil loss whilst the bike is on the side stand. Finally the clutch cable should be readjusted (at both ends).
Job done and all good – well not quite. The heavy EBC springs made the clutch lever action really hard going. More crucially, when the clutch warmed up, it would stick and drag really badly, to the extent of the bike creeping forward even with clutch lever fully in! It also would be impossible to get into neutral whilst warm, unless I hit the kill switch – less than ideal. In trying to resolve this I tried a number of things and replaced more parts I suspected could be at fault:-
- Re soaked clutch plates in oil and ensured steel plates all faced same direction with slightly round edge outwards – small improvement.
- New clutch cable – no difference.
- New long clutch push rod (and it’s oil seal), as old had corroded at sprocket end possibly hindering movement and worn notches in ends – no difference.
- New TRW steel clutch plates, as old were quite scorched and probably should have been replaced – no difference
- Inspected clutch basket fins for notching that may hamper plate movement and very lightly filed any smooth – no difference
- New shot clutch push rod (and o-ring) at basket end – no difference.
Swapped EBC springs for genuine Yamaha springs – clutch drag 100% resolved!
Fixed now? Not so fast, the genuine Yamaha clutch springs did made the gear changes super smooth and easy, neutral a doddle to engage, but it did occasionally give me a bit of clutch slip still, even with the brand new plates… Nothing like as bad as the old worn clutch, but now and again it is there.
I suspect the EBC springs were too stiff, not letting the plates release enough. The Yamaha springs looser, but maybe slightly too loose. Also the EBC springs measured 1mm longer… (3.9mm vs 3.8mm – though Haynes manual reckons they should be 3.4mm!) I briefly tried three of each, half EBC, half Yamaha springs , but this just brought back clutch drag woes.
I might experiment with other brands of springs that promise to offer a happy medium, but in the mean time, I’m sticking with genuine parts. Moral of the story, genuine parts often rule and should not be dismissed, even if considerable more expensive.
Addendum: I found the brand new replacement genuine Yamaha springs to light, often still get clutch slip. On measuring I discovered the new replacements were 1mm shorter than the original old springs – so I reverted back to these, which reduced clutch slip considerably, irradiating it except when first pulling away cold.