Uphill Racers

Go Back   Uphill Racers > Technical > Engine & Chassis
Register FAQ Members List Calendar Downloads Mark Forums Read

Reply
 
Thread Tools Display Modes
  #21  
Old 03-10-13, 14:28
Clive Austin's Avatar
Clive Austin Clive Austin is offline
The Empire Strikes Back..
 
Join Date: Jul 2009
Location: Worcestershire
Posts: 916
Clive Austin will become famous soon enough
Will do. For belt and bracers I've just put a dial gauge on the car. 1.4-1.5mm basket travel. I also clamped up the other side to check for flexing of the slave housing - no detectable flex so that's another possibility eradicated.

Just praying the steels and oil fix it.

...as for pulling my hair out...!
__________________
Latent Magnificence!
Reply With Quote
  #22  
Old 03-10-13, 15:14
T13EES's Avatar
T13EES T13EES is offline
Senior Member
 
Join Date: Aug 2008
Location: Stock in Essex
Posts: 150
T13EES is on a distinguished road
I have the 1000 GSXR K8 in my Jedi and suffered clutch drag after a number of meetings. New clutch plates and using the correct engine oil (Millers ZFS 10w40) suitable for a wet clutch solved the problem. I have a Jebs wet billet sump and have always slightly overfilled and put a full 4 litres in. When I change the oil I measure what comes out and have always near as dammit got a full 4 litres back out.
Quote:
Originally Posted by Clive Austin View Post
... I love my radii...

The bite point feels like it is in a normal place - towards the top-side of the mid point I'd say. Our issue is that we get drag of varying degrees when the clutch is fully depressed leading at times to needing to be held back by the wing on the start line. It also makes it impossible to get back into neutral without turning the engine off. We get no clutch slip under load once we are up and running.

We have blead (sp?) the thing a million times both ways, replaced the slave cylinder seals and fitted a larger master cylinder. No difference. I then put a 4.7mm dia ball bearing in between the slave and the actuation push rod to test release vs slip in case I wasn't getting enough travel for some reason. Little / no difference. I then added more packing until I got to the point where with the pedal fully released in gear there was massive clutch slip. However, it still struggled to go into neutral with the clutch depressed and still "rocked" forward on its wheels when revved. This suggests to me that it can't be clutch travel or hydraulics but this is what I keep being told it "must be". If I put any more packing in I think I'd push the clutch out through the garage wall ;-). Just to be sure I stripped the clutch and polished all the plates and cages to ensure they weren't snagging on anything. Cut my fingers to bits but made s0d all difference.

I've also been told by a Suzuki tech that the oil is critical. I originally used Silkolene Pro 4 Plus 5-40 fully synthetic but the tech chap told me this will have contaminated the plates and we should use Comp 4 10-40 semi synthetic only. Apparently we will need a new clutch incl steels to cure. However, others, including the chap that built the engine, don't share this view and say the fully synthetic should be fine. I've bought 6l of Comp 4 and dropped all the 5-40 out just to be on the safe side once I change the clutch plates.

With our wet sump we also fill higher than the factory spec. It could also be that filling to a higher level is submersing the plates deeper in oil and causing more viscous drag. No way of testing until the whole thing is back in one piece with a new clutch although a quick test with a lower oil level on the old clutch didn't seem to make much difference. Odd that no other K8 pilots have hit this issue though if this is the problem.

It feels a bit like the economy - everyone has a clearly defined and firmly held view of what it is - and each one is different! In reality it is probably a combination of all of the above.

I am awaiting delivery of a set of clutch plates so want to make absolutely sure that everything else is OK whilst it is in bits. Hence looking at travel whilst the cover is off (I've sent you a spread sheet - and no I'm not kidding ;-)).

Answers on a postcard please?

Chunter, chunter...
Reply With Quote
  #23  
Old 03-10-13, 19:56
Fireblade's Avatar
Fireblade Fireblade is offline
Senior Member
 
Join Date: Jan 2007
Location: Quahog, RI
Posts: 2,524
Fireblade is a jewel in the rough Fireblade is a jewel in the rough Fireblade is a jewel in the rough Fireblade is a jewel in the rough
Quote:
Originally Posted by Clive Austin View Post
... I love my radii...
iranoff said something similar like... I love my Pi...
Reply With Quote
  #24  
Old 04-10-13, 19:22
Clive Austin's Avatar
Clive Austin Clive Austin is offline
The Empire Strikes Back..
 
Join Date: Jul 2009
Location: Worcestershire
Posts: 916
Clive Austin will become famous soon enough
All the bits arrived today so I replaced the plates and springs. New semi synthetic oil. Other than shearing off a clutch cover bolt it all worked a treat. No drag and selects neutral. Haven't had chance to do the inquest yet but at least we can go racing tomorrow!

I'll post the cause when I find it. Thanks for all the suggestions and ideas though.

C
__________________
Latent Magnificence!
Reply With Quote
  #25  
Old 04-10-13, 19:58
marengo 3 marengo 3 is offline
Junior Member
 
Join Date: May 2011
Posts: 5
marengo 3 is on a distinguished road
Hi Clive, just a thought but Darren and I had slight issues with clutch drag with our Force all those years ago! I always put it down to over-filling and tried to manage the situation by blipping the throttle once or twice before selecting 1st gear. I assumed rightly or wrongly that this technique helped to throw 'trapped' oil out from between the plates, but I was never sure and didn't investigate further! Come to think of it, I can remember doing the same trick occasionally with Marengo 3 ever since the 1st engine failed on me at Loton that time. PS. My Tony Pashley-built Yamaha 600 engine is up for sale if anyone is interested??
Reply With Quote
  #26  
Old 04-10-13, 20:29
team knifedge's Avatar
team knifedge team knifedge is online now
Return of The Sith
 
Join Date: Jan 2007
Location: I can hear The World Famous
Posts: 1,097
team knifedge will become famous soon enough team knifedge will become famous soon enough
Yippeeee, a racing we will go....
Reply With Quote
  #27  
Old 05-10-13, 08:12
AllanMcD's Avatar
AllanMcD AllanMcD is online now
Senior Member
 
Join Date: Jan 2009
Location: Dalbeattie SW Scotland
Posts: 931
AllanMcD will become famous soon enough
Racing only a few months until I have a go
Allan
__________________
aandgmotorcycles co uk
Reply With Quote
  #28  
Old 05-10-13, 20:56
team knifedge's Avatar
team knifedge team knifedge is online now
Return of The Sith
 
Join Date: Jan 2007
Location: I can hear The World Famous
Posts: 1,097
team knifedge will become famous soon enough team knifedge will become famous soon enough
Just like to thank Clive for some awesome work this week...enough to give him a be PB at The Lawns
Unfortunatley we've now got a clutch slip problem- so the curse of clutches remains
Reply With Quote
  #29  
Old 06-10-13, 06:44
Clive Austin's Avatar
Clive Austin Clive Austin is offline
The Empire Strikes Back..
 
Join Date: Jul 2009
Location: Worcestershire
Posts: 916
Clive Austin will become famous soon enough
...spoke too soon. It worked perfectly at Prescott for 6 runs and then slipped badly on the 4th runs. Back to the drawing board...
__________________
Latent Magnificence!
Reply With Quote
  #30  
Old 07-10-13, 10:55
Clive Austin's Avatar
Clive Austin Clive Austin is offline
The Empire Strikes Back..
 
Join Date: Jul 2009
Location: Worcestershire
Posts: 916
Clive Austin will become famous soon enough
Lots of comment on Google relating to micro bubbles causing problems with hydraulic clutches if the clutch line comes into contact with the frame and picks up vibration. Has been known to cause both drag and slip depending on the situation and conditions. Anyone come across this?

C
__________________
Latent Magnificence!
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 19:42.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright© 2007-2018 Uphill Racers www.uphillracers.com