[Ex Jap Scrap]

Good day all.

So I took delivery of my bike on Saturday.

All seemed well.

Went for a bit of a ride with some close mates and my Fiance.

Sunday just my Fiance and I go out for a quick ride. On the return trip I note that the clutch is slipping between 6000 and 7000 rpm?

I had adjusted the lever for my hand span,so I adjusted it back to the original span and it goes away?

Now it is back again?

The mechanic changed the pressure plate as it was going to become an issue, he checked the stack height and all seemed fine?

Any ideas?

Currently taking it easy on he throttle which is fine past 6000 rpm, but anything past half way on the throttle and it will slip between 6000 - and 7000 Rpm?

 

[1fast750ss]

The stack height may be fine as total, but you should check each friction and steel plate individually too. If the old owner added a plate or two to bandaid the initial slipping, the plates may now be too thin individually, getting worse as you go WOT. The torque of your beast is pretty serious compared to the Big 4 Jap stuff.

Typically most plates have a 10-20% variance on minimum thickness. A 2mm plate would be about 1.8mm, etc.

 

[tye1138]

Umm, you MUST change the pressure plate with a slipper, its not a recommendation but a requirement. I'm concerned your mechanic didn't know that and made up some reason. That to me is a whole bunch of red flags. I think the answer lies right there, something is very fishy.

 

[Ex Jap Scrap]

Hmmmmm........thanks for the advice thus far.

Will have a look into it.

The original pressure plate was changed due to it being out of spec.

What I have noticed is that it's not a constant issue.

Thinking I should maybe just buy new fibres, steels and just rebuild the entire clutch.

Out of curiosity, recommended replacement fibre and steel clutch kits?

I have seen some saying the OEM stuff is good but others do not agree?

 

[1fast750ss]

Clutch Plate Kit EVO Kevlar

They work great for the street and track. Don't forget you have a member discount with DUCORG10 code.

 

[tye1138]

The original pressure plate was changed due to it being out of spec.

The non-sipper pressure plate has teeth in it, which engage into the output shaft (hub) of the clutch. The slipper can't have teeth because the hub pushes out and disengages the clutch pack, thats how it works. So maybe the first pressure plate from STM was out of whack? But yea, something doesn't quite add up.

 

[Ex Jap Scrap]

The non-sipper pressure plate has teeth in it, which engage into the output shaft (hub) of the clutch. The slipper can't have teeth because the hub pushes out and disengages the clutch pack, thats how it works. So maybe the first pressure plate from STM was out of whack? But yea, something doesn't quite add up.

He did replace it with another STM pressure plate though.

But I reckon I'm just going to rebuild the stack and get it done.

 

[Ex Jap Scrap]

Clutch Plate Kit EVO Kevlar

They work great for the street and track. Don't forget you have a member discount with DUCORG10 code.

Excellent!

Will definitely keep this in mind for sure!

It makes sense to rebuild the clutch from scratch as opposed to trying to sort it out through someone that will try and use the cheapest option.

 

[Ex Jap Scrap]

Good day Everyone.

So a bit of an update here.

I havent ordered the clutch pack as of yet - still waiting on the funds - banks can be shyte slow in releasing savings here due to tax implications apparently?

On the flip side I decided to bleed the clutch to see if it would make any difference at all.

Needless to say, the slip is now gone?

The reservoir is now half - from full originally.

But there isnt any slip?

 

[EL Twin]

Have you replaced levers with aftermarket? Is there adequate freeplay at end of the lever? (12-20mm)? Air space is necessary in the reservior to allow for fluid expansion due to heat. If the lever has inadequate freeplay the oil return hole in the master cylinder can be closed off and the clutch will slip when the expanding oil has nowhere to go.... just as if you pulled the lever slightly the expanding oil lifts the pressure plate, allowing the clutch to slip under heavy loads. Many people here in the past have had trouble with front brakes locking up for the same reason. Just something else to check before spending any $$$.

 

[Ex Jap Scrap]

Thanks for the advice there El Twon.

That's what I was thinking as well when I took her out for a test ride and had no issues at all with the usual slip.

Now the next question I have is: should I still change the clutch or not?

Perhaps just change it anyway and keep the stocker as spare should the damage not be too bad?