« previous next »
Pages: [1]   Go Down

Author Topic: Slipping Clutch  (Read 2276 times)

0 Members and 1 Guest are viewing this topic.

Offline CB500_k2

  • Hot Shot
  • ***
  • Posts: 351
  • Wrenching makes a good retirement.
Slipping Clutch
« on: August 16, 2005, 07:19:01 AM »
My CB 500 project has reached the point where I feel more comfortable pushing the little machine harder.  I have run into a clutch slipping problem when changing gears with full throttle over 7000 RPM.  I have replaced the old friction pads with Barnett Kevlar disks, retaining the original steel discs and springs.  I believe the steel discs and springs are stock.  The length of the springs was just a shade over stock length so I figured they were ok.  After these modifications clutch performance was better but there was still a little slippage when shifting at high RPM.  The clutch cable is new and the big clutch adjusting screw is properly set up for push rod free play. I am using Castrol GTX oil. Barnett says they do not have heavy duty springs for my application. I am not sure whether the springs on the 500 and 550 are the same.  I really don’t want to baby my machine.  Have any of you knowledgeable folks any suggestions? 

Thanks.

Tom
Logged
Too many bikes -- too little time
1973 CB500
1974 CB350 - sold
1975 CB400F SuperSport
2000 Ducati Monster Dark

Offline bryanj

  • Really Old Timer ...
  • *******
  • Posts: 13,979
  • CB500 Number 1000036
Re: Slipping Clutch
« Reply #1 on: August 16, 2005, 09:33:07 AM »
the 500 clutch always slips if pushed hard.Personally think its the inertia in the pushrod/adjuster mechanism. road these for years and although it slipped it never wore out
Logged
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline clarkjh

  • Expert? If only.
  • Expert
  • ****
  • Posts: 1,385
  • Surely and Samson are now Co-habitating
Re: Slipping Clutch
« Reply #2 on: August 16, 2005, 02:07:19 PM »
If the oil has anti-friction coatings in it that will cause the clutch to slip.

Got this from the Castrol sit

Logged
SOHC/4 #3328
SOHC/4 Gallery: http://www.sohc4.us/gallery/v/members/personal/clarkjh/
1974 CB550, 40000 Miles
1980 GL1100, 102789 KM - Back on the road after a complete engine rebuild. 
*** Why, oh why, is it always head gaskets with me?***

Offline number13

  • Hot Shot
  • ***
  • Posts: 521
  • 1973 CB500, 2002 VT750DC
    • Sound Exchange
Re: Slipping Clutch
« Reply #3 on: August 16, 2005, 02:26:37 PM »
Had the same problem on my bike, identical to yours BTW, and had
good results shimming the clutch springs. Just use 4 identical washers.
VIOLA!

Logged
Bikes parked out front mean good chicken-fried steak inside.

Offline CB500_k2

  • Hot Shot
  • ***
  • Posts: 351
  • Wrenching makes a good retirement.
Re: Slipping Clutch
« Reply #4 on: August 16, 2005, 03:30:31 PM »
I was thinking about using shims to compress the clutch springs.  How thick were the ones you used?

Tom
Logged
Too many bikes -- too little time
1973 CB500
1974 CB350 - sold
1975 CB400F SuperSport
2000 Ducati Monster Dark

Offline number13

  • Hot Shot
  • ***
  • Posts: 521
  • 1973 CB500, 2002 VT750DC
    • Sound Exchange
Re: Slipping Clutch
« Reply #5 on: August 16, 2005, 05:06:02 PM »
Er...I didn't actually measure them, just dug around the workbench. I do recall they were thinner than
most, possibly 1/32 or so.
Logged
Bikes parked out front mean good chicken-fried steak inside.

Offline Kevin D

  • Old Timer
  • ******
  • Posts: 2,869
  • SE Michigan
Re: Slipping Clutch
« Reply #6 on: August 17, 2005, 01:15:07 PM »
 I think I recall using NGK D8ES spark plug washers for clutch spring shims on my 750. I don't know if they will work on a 500. 
Logged
71 CB750 K1
104,000 miles
Original Owner
———past———
70 SL100/125/150
70 Candy BlueGreen CB 750 K0
————————————————-
Former Honda parts kid/counter kid/do all
—————————————————————-
Whether you think you can or think you can’t, you’re right
Genius is 99% perspiration, 1% inspiration

Offline CB500_k2

  • Hot Shot
  • ***
  • Posts: 351
  • Wrenching makes a good retirement.
Re: Slipping Clutch
« Reply #7 on: August 17, 2005, 01:33:56 PM »
Thanks for the suggestion.  When I get the clutch apart again I will see if sparkplug washers will fit.  Anyone know where to get heavy duty clutch springs for a CB500?  Barnett does not make them any more.
Logged
Too many bikes -- too little time
1973 CB500
1974 CB350 - sold
1975 CB400F SuperSport
2000 Ducati Monster Dark

Offline CB500_k2

  • Hot Shot
  • ***
  • Posts: 351
  • Wrenching makes a good retirement.
Re: Slipping Clutch
« Reply #8 on: August 19, 2005, 02:01:52 PM »
Well I found some oil pan drain plug washers which fit into the clutch basket perfectly.  They were about 2 mm thick.  The clutch pull is now a little stiffer and the slippage is completely gone.  Thanks for the suggestions regarding shimming the clutch springs.

Tom
Logged
Too many bikes -- too little time
1973 CB500
1974 CB350 - sold
1975 CB400F SuperSport
2000 Ducati Monster Dark

bike54

  • Guest
Re: Slipping Clutch
« Reply #9 on: August 19, 2005, 06:26:07 PM »
hi
if your after a good oil that works well try castrol classic its the formula of castrol gtx befor they updated it with all the synthetics it has good reveiws by all the clasic car and bike men in the uk that have used it

bike54
Logged
Pages: [1]   Go Up
« previous next »