BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: chrisx1 on 29 Jul, 2023, 14:25

Title: A65 clutch problems
Post by: chrisx1 on 29 Jul, 2023, 14:25
Any clutch gurus on here in the Evesham area. I can't get it set up right. Thought I had it but it's gone back to being stiff and won't disengage completely. Whenever I stop in gear it's trying to creep forward. Also gets a false neutral between 4th and 3rd.
Title: Re: A65 clutch problems
Post by: Allan G on 29 Jul, 2023, 21:47
Sounds like you might have a clutch and a gearbox camplate issue if your getting a false neutral between 3-4th
Title: Re: A65 clutch problems
Post by: chrisx1 on 29 Jul, 2023, 22:03
So do you suspect worn camplate?
Title: Re: A65 clutch problems
Post by: rhyatt on 30 Jul, 2023, 08:24
Surely the place to start is the clutch actuation and the pushrod and equality of lift on the pressure plate.
Get it slipping nicely at separation and gripping enough to kick over.
Title: Re: A65 clutch problems
Post by: DAVE BRADY on 30 Jul, 2023, 10:31
Hi,

Have you had the clutch apart to see if there is excessive wear in the slots for the tabs on the plates?  The creeping when the lever is pulled in does strongly suggest sticking plates.  Any resistance here will make the clutch heavy and may prevent the plates from separating properly.
If you have the '3 balls' mechanism then setting it up right is crucial as there not much 'lift' in this setup to start with.
You have probably done this but completely slacken off the cable and adjust the screw in the centre of the pressure plate so that it is just touching the pushrod and back it off a 1/4 to 1/2 half a turn.  Check the '3 balls' mechanism. There should be almost no movement.

Dave.
Title: Re: A65 clutch problems
Post by: chrisx1 on 30 Jul, 2023, 14:43
It's 68 not 3 ball arrangement. I have rebuilt the clutch with new Cush drive rubbers, no wear on inner or outer basket. I need to look at cable run see if that can be better.
Title: Re: A65 clutch problems
Post by: Gup holland on 30 Jul, 2023, 15:06
Did you start with a clutch plate (cork) or a plain one, if this is wrong it also wants to creep forward when clutch is in. You had to end with a plain (steel) plate.
Was my first experience when i bought my BSA.
Title: Re: A65 clutch problems
Post by: chrisx1 on 30 Jul, 2023, 16:14
Cork first, plain last.
Title: Re: A65 clutch problems
Post by: Allan G on 30 Jul, 2023, 20:35
Quote from: chrisx1 on 29 Jul, 2023, 22:03
So do you suspect worn camplate?

A65's have good boxes, they don't jump out of gear for no reason.

The biggest issue they have is the indent plunger is too pointy and can wear a groove in the cam plate, when it's worn all the way the track it leaves is smooth, the box relies on that plunger holding against the indent of the cam plate track. When mine started jumping out of gear, it was because of this.

New cam plate and polished the plunger to a more rounded end and it's been fine ever since.

Clutch issue could be you need to back the adjustment screw off, especially if the clutch plates were new and they have started settling in, the free play you had before has
Now been taken up.
On my 68 I removed the sprung attachment on the cable, the idea being that you can change the cable without removing the outer timing cover, however without it and having a cable with a longer inner (like the first incarnations of unit twin) you will have much more clutch pull available to you.
Title: Re: A65 clutch problems
Post by: chrisx1 on 05 Aug, 2023, 11:34
Still having problems. I took the clutch apart again and refitted it. I cannot seem to get the pressure plate even. The part of the plate that stands out most seems to move about, confusing me as to where to tighten and or loosen. Has anyone else had this issue.
When I first ride it, it seems to be working reasonbly ok but after a short while it starts to drag and I shudder at the thought of traffic junctions etc.
Title: Re: A65 clutch problems
Post by: LightningAndStarfire on 05 Aug, 2023, 13:24
Perhaps a new set of springs is a remedy. Calibrated to the same force vs lenght.
Title: Re: A65 clutch problems
Post by: chrisx1 on 05 Aug, 2023, 14:21
They are brand new springs but one is shorter than the other two.
I probably should go back to my supplier and make sure all three batch up.
Title: Re: A65 clutch problems
Post by: rhyatt on 05 Aug, 2023, 16:14
Would they have a free spring length to know what you're dealing with lengthwise.
Title: Re: A65 clutch problems
Post by: rhyatt on 05 Aug, 2023, 18:15
It's not been mentioned but viscosity of primary oil may play a part in dragging( excluding for a moment the mechanical situation).
I often use ATF in primary chaincases.
And of course the correct viscosity in the gearbox itself can play a part in the easy sliding of the dogs on shafts.
Title: Re: A65 clutch problems
Post by: chrisx1 on 05 Aug, 2023, 18:22
It's worth giving a try.
Title: Re: A65 clutch problems
Post by: Allan G on 07 Aug, 2023, 22:12
Get a set of springs from LP Williams, there's a lot of rubbish springs sold by suppliers who would normally be given good credit. I went down the same exact route and in the end gave up and fitted the Bob Newby belt. I'd got it about right just after I ordered the belt, but 12 years on the belt has given me zero issues so I'm glad I ditched the original setup.
Title: Re: A65 clutch problems
Post by: chrisx1 on 08 Aug, 2023, 08:33
I have ordered a set of springs from L P Williams.
Thank you.
Title: Re: A65 clutch problems
Post by: Allan G on 08 Aug, 2023, 12:28
Quote from: chrisx1 on 08 Aug, 2023, 08:33
I have ordered a set of springs from L P Williams.
Thank you.

no problem, the ones I ordered were for a T120, but they are the same. I have always found their service to be top notch also.