BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: blackeyeian on 05 Dec, 2018, 11:12

Title: BSA A50 1962 CLUTCH STICKING
Post by: blackeyeian on 05 Dec, 2018, 11:12
HI   I AM EXPERIENCING CLUTCH STICKING - AFTER A 15 MILE ISH RIDE PARK UP - THE CLUTCH DOESN'T WANT TO RELEASE.  SO I ROCK (A LOT) IT IN GEAR SOMETIMES IT RELEASES SOMETIMES I HAVE TO ROLL IT AND PUT IT IN GEAR WHILST MOVING, ONCE INTO 3RD GEAR IT RELEASES ITSELF.  THE LAST TIME I TOOK THE PLATES OUT I FOUND THE CENTRE 4 PLATES STUCK - ISH TOGETHER.   I  PRISED THE PLATES APART - THE CONDITION SEEM OK.  THEY SEEM FLAT.
I AM RUNNING 2 EGG CUP FULL OF CASTROL TQF IN THE PRIMARY.

IS THERE A FIX OR A CLEANING SOLUTION FOR THIS PROBLEM.
ALSO, IF I NEED TO REPLACE THE PLATES WHICH ONES WOULD YOU SUGGEST, AND FROM WHICH REPUTABLE SUPPLIER, AS THERE SEEM TO BE MANY AVAILABLE.

THANKS IN ADVANCE
IAN
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: A10 JWO on 05 Dec, 2018, 16:19
Could be wear on the basket and the plate tangs ( think that's the word ) interlocking causing a lock. I could be barking up the wrong tree ! Pull it down and get the magnifying glass out. I get my plates  from Kidderminster M/C's.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: bikerbob on 05 Dec, 2018, 17:22
Different bike but similar clutch A10 I had sticking plates years ago it was caused by using engine oil in the primary I changed to 20 grade fork oil on advice of a then well known restorer in my area, since then on all my bikes I have used 20 grade fork oil in the primary and never had any more serious sticking problems, sometimes have to press the kick start 2 or 3 times to freeup before starting.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: blackeyeian on 06 Dec, 2018, 10:33
THANK YOU SO MUCH FOR YOUR INPUT - I HAVE JUST REMOVED THE CLUTCH PLATES AND THE FIRST 5 DISCS ARE STUCK TOGETHER - WILL SMOOTHING THE TANGS, CLEANING THE PLATES WITH METHYLATED SPIRIT AND USEING 20 GRADE OIL BE THE BEST CHANCE OF A CURE? 
SHOULD THESE PLATES BE REFITTED DRY OR SMEARED IN OIL?
OR SHOULD THESE PLATES NEED REPLACING - IF SO WHIT WHAY PLATES - SURE FLEX OR NON SUREFLEX?
THANKS AGAIN
IAN
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: A10 JWO on 06 Dec, 2018, 17:27
Put your plates in order on a level surface and see if the bundle feels spongy when you push down or does it all rock about ? I bought Surflex last time.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: ROYC on 07 Dec, 2018, 10:55
I have a new SRM clutch and that stick too.
I have tried parking up with the clutch lever pulled back to the handlebars and it makes no difference.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: Caulky on 08 Dec, 2018, 10:58
If you want to clean the clutch plates, soak them in paraffin (kerosene) overnight. Then dry them and fit them dry.
Before attempting to start the engine, pull the clutch lever (ignition off) and kick until the clutch spins freely.
If this can not be achieved, adjustment is neccessary.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: blackeyeian on 08 Dec, 2018, 14:24
Thanks again for the info - I was talking to an old motorcycle mechanic who suggested soaking the plates overnight in 20 grade oil then refitting, as the most likely cause of them sticking is that they are too dry.
That seems to be at odds with your suggestion - confused!
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: Martin on 08 Dec, 2018, 19:49
The oil for the primary chaincase should be a 20W50 mineral oil; the same oil that you use for the forks.

I spent a lot of time getting my A65 clutch to operate properly and, assuming there's little or no difference in principle between that and an A65 clutch, suggest you place all the clutch plates into a bath of clean petrol, leave them there overnight, then remove them and wipe the petrol off with some clean linen and allow the rest to evaporate. That done, wipe the bonded plates very lightly with fresh 20W50 - too much and they'll stick to the driven plates, which should be left dry. You want them so that they'll slide freely when you apply the clutch lever. Replace the plates and don't over-tension the springs. The clutch nuts on my bike sit proud of the bolt heads, making application of the clutch lever much easier.

I've had no clutch problems since. Best of luck.
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: blackeyeian on 11 Dec, 2018, 11:51
THANK YOU FOR ALL THE TIPS -I HAVE DECIDED FIRSTLY TO SOAK THE PLATES IN OIL OVERNIGHT - REFIT AND SEE IF THERE IS AN IMPROVEMENT. IF NO JOY I WILL SOAK THEM IN PETROL AND FIT THEM DRY. HOPEFULLY ONE OF THESE WILL SORT THE CLUTCH OUT.
I WILL LET YOU KNOW MY RESULTS AFTER ABOUT 100 MILES OR SO
THANKS AGAIN
IAN
Title: Re: BSA A50 1962 CLUTCH STICKING
Post by: Dean Southall on 11 Dec, 2018, 21:06
All these replies are interesting but don't address the issue of the clutch sticking after  the bike has been ridden for a while. I also have this problem with my clutch and would be interested in any suggestions. Is it to do with the clutch warming up?