Clutch issues... RESOLVED!!!

[skiracer]

So, on my 76 175 XC, after changing out the clutch basket, plates, actuator, push rods, and cable, I still have a hard pulling clutch.  Yes, the cable route has smooth bends.  Any ideas on what else could be making it a hard pull?

1976 250 MC5 Original Owner
1976 Penton 175 XC

[Carl Hill]

There is a small pin in those actuators that can get a notch worn in it. I changed the pin in mine and it made a huge difference. Al has them.

[G Ellis]

Might have 250, 400 clutch springs in it.

[skiracer]

Don't think so. The ones I put in measured the same as what came out. Where can I get some 125 springs?

quote:Originally posted by G Ellis

Might have 250, 400 clutch springs in it.

1976 250 MC5 Original Owner
1976 Penton 175 XC

[Toolsurfer]

Not only the length, check the diameter of the spring wire versus a known stock spring . Length and wire dia. or mechanical friction somewhere . Check every component for binding one piece at a time . From what I am told that's the way John Penton would have approached it . You'll get it just move methodically . Good luck William

[Pat Oshaughnessy]

Last of all get the best cable you can  buy & take it off the bike hang it up & Lube it till oil comes out the bottom . Do this every time betwen races. It does make it work . At least it did for me . Now we have hyd. clutches this is why.

[Rocket]

It makes a difference on how far you have the nuts screwed in on the clutch springs.
RCG

[skiracer]

The springs are the same as what came out

quote:Originally posted by Toolsurfer

Not only the length, check the diameter of the spring wire versus a known stock spring . Length and wire dia. or mechanical friction somewhere . Check every component for binding one piece at a time . From what I am told that's the way John Penton would have approached it . You'll get it just move methodically . Good luck William

1976 250 MC5 Original Owner
1976 Penton 175 XC

[skiracer]

I have the nuts screwed in just enough so that it doesn't slip

quote:Originally posted by Rocket

It makes a difference on how far you have the nuts screwed in on the clutch springs.
RCG

1976 250 MC5 Original Owner
1976 Penton 175 XC

[skiracer]

brand new cable

quote:Originally posted by Pat Oshaughnessy

Last of all get the best cable you can  buy & take it off the bike hang it up & Lube it till oil comes out the bottom . Do this every time betwen races. It does make it work . At least it did for me . Now we have hyd. clutches this is why.

1976 250 MC5 Original Owner
1976 Penton 175 XC

[454MRW]

Don't forget a dab of grease on the brass ferrule that the cable end rides against the clutch release pivot arm.

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Penton
1976 MC5 400
1978 KTM 78 GS6 250
L78-79 MX6 175-250 KTM's
1976-78 125-400 RM's
2007 CR125R Honda
1977 MC250 Maico
2017 KTM Freeride 250R

[DKWRACER]

If you want to troubleshoot the actuation part, I would eliminate the cable temp. by using the box end of a wrench over the clutch actuator arm....have also used a crescent wrench too, seems mac-giver at this point, but there are a lot of friction points/hazards, Bobby Lucas had a great article about clutch setup, involved using a dial indicator to verify that the outer plate moves uniformly, once again friction and moving parts, will cause issues. Have noted oil-canned steel plates, basket legs with burs, clutch plate fingers burs/sharp edges. Bearing surface on the outerplate that touches the rod off center, ie. the rod wobbles off center, runs the gammut...Kent Knudsen also re-routed the clutch cable too... Best of luck!!!

Thomas Brosius

[johnacapp]

Tom,
Can you tell me where I can find  "Bobby Lucas had a great article about clutch setup"?

PS You Supplied me with a used Super trapp that I made a trick attachment for my 77 GS6 worked out great
Thanks

John Capp

[DKWRACER]

That one might be hard to locate, perhaps Skip Miller, Al B. or Paul D.
may have a copy, some where in the archives, I do know Glenn G. in Houston has a copy, along with the Patriot Penton...

Thomas Brosius

[Mike Rosso]

Also make sure the actuator arm at the engine is not going over center when the handlebar clutch lever is fully pulled to the bar. Anything past 90 degrees at the actuating arm and you are losing mechanical advantage. A little dab of grease or dry graphite on the cable barrel end at the clutch lever will also help.

Have you measured the thickness of the new clutch plates and compared that to new originals? If there are dimensions given for all of the thicknesses of the original plates and you add them together that will give you the target to meet with any new plates. If you calculate the total height of the new clutch plates and that figure is even a millimeter or two higher you will have more clutch spring preload even with the correct springs. This was always a problem with availability of older model KTM clutch plates and all we did was reference the original parts list plate dimensions given in the KTM parts books and get the total dimension of the original stack height. At that point (for conversation) if the total stack height equaled 32mm that was the target to get too or as close too by substituting STEEL clutch plates and even combining STEEL plates together. If the base steel plate was 2.0mm originally and no longer available then two 1.0mm steel plates would work fine in that position. You can do this with any clutch on any bike as long as you can maintain the ORIGINAL total clutch plate(s) stack height. The clutch doesn't know what clutch plates are in there it just remembers what the original clutch stack height is supposed to be and how much mechanical lift (movement) it was designed with.