Clutch vibration on take off solved

[Aussiedrew]

Have had the Z900 two months now. 2017 with 25k on the clock. Absolutely love the thing, though it developed a harsh vibration from the clutch when taking off in first. Always happens on take off when cold, and tended to fade once hot but has been getting worse. Cable adjusted correctly. Fresh oil. No clutch slipping. Just a vibration/grinding feel as the bike initially pulls away from a stop at anything other than a snails pace. Quite unpleasant!

Seems this was an issue with the old Z1000's and a lack of oil supply to the plates. The solution was to drill the clutch basket to let more oil in but was apparently resolved once the bike was upgraded to a slipper. In saying that, I'm not the first to report the same issue on the 2017 Z900 or even some early Z900RS's. The 2018 friction plates were updated so it seems noone with 2018+ models reports the issue.

Anyway, bought some Whites friction plates and hoped for the best. Once they arrived, tilted the bike over (wheels on small blocks, resting on side stand) and carefully popped the clutch cover without busting the gasket (yes this part was a gamble). And pulled out some pretty damn dry clutch plates. As is, no oil residue on them at all. The plate closest the engine had just a little on the fingers at the bottom but that was it, after last riding the bike 12 hours earlier.

Other than that, no visible wear at all. Steels and frictions plates looked completely fine and measured at the upper end of the service limit for the stack width. The 1st and last friction plate differ from the other 7, where the 2018 model has 9 of the same (as the 7).

Anyway, I'm not sure how they "solved" the issue in 2018 by switching those two plates as it really seems like oil supply is the issue. Though the basket is actually already drilled so though I was planning to drill it as well as replace the plates, I skipped that part. The new Whites plates have angled cuts in the material rather than square blocks. A bit of research told me some people recommending one direction so it throws the oil outwards, and some the other direction so it throws the oil inwards. I chose inwards to try and keep as much of the oil within the basket as possible. Who knows though, could well make no difference at all in reality.

Anyway, soaked the plates a couple of hours. Reinstalled the clutch pack. Whacked on the clutch cover and went for a spin. Problem solved, a perfectly smooth clutch. Maybe I could have gotten away with just re-oiling the stock plates. Maybe not. What's going to stop these plates drying out again over time? Who knows. Was a pretty cheap and quick fix though and now I can get on with enjoying this really awesome bike. One of the best I've had in many years.

[Aussiedrew]

As the cover came off. Very small amount of oil residue within the basket.


Plate is devoid of almost any oil. Feels dry to the touch.


Shows holes already drilled in the basket (unless someone's actually been in here before me).


New friction plates, unsoaked. I installed them in the opposite direction to as shown.

[M2014RN]

Excellent post! I'll review this once again prior to replacing the plates. I have a 2017 with 27k that has the same symptom when cold. I think I'll be purchasing the same plates as they appear to have an increased surface area of friction material. Thank you.