The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: Greybeard on 21.07. 2018 18:14

Title: Primary needs
Post by: Greybeard on 21.07. 2018 18:14
Today I've had the opportunity and motivation to work in my very hot oven shed. Have I mentioned that in the UK we are having a very unusually hot summer?

I last used my bike to do a BSAOC weekend. I noticed while I was away that I had a leak from the Primary case, so today. I took the cover off and found the inside as dry as a witches tit! The chain is knackered for sure. I can probably buy a new duplex chain. More worrying is the Clutch Chainwheel, (67-3271) which feels rather hooked. I'll put a Wanted Ad in the appropriate place but has anyone got anything useful to say about this? Can I try to smooth off the hooking with a file?
Title: Re: Primary needs
Post by: RogerSB on 21.07. 2018 19:35
Hi GB, in my humble opinion you'd be best replacing the chainwheel cos if it's not right it'll quickly destroy your newly purchased chain  *sad2* , as will the hooked one if you leave it.
Title: Re: Primary needs
Post by: Greybeard on 21.07. 2018 20:13
Hi GB, in my humble opinion you'd be best replacing the chainwheel cos if it's not right it'll quickly destroy your newly purchased chain  *sad2* , as will the hooked one if you leave it.
I understand that the hooked clutch sprocket will knacker the new chain. I'm having trouble with your post Roger; you seem to be referring to two items. The engine sprocket is ok. Is that what you mean when you say chainwheel?  *conf*
Title: Re: Primary needs
Post by: RogerSB on 21.07. 2018 21:15
Is that what you mean when you say chainwheel?  *conf*

Not engine sprocket, what you referred to - the clutch chainwheel.

I was referring to your question about smoothing off the hooks with a file on your hooked one - but probably didn't make myself very clear.
Title: Re: Primary needs
Post by: muskrat on 21.07. 2018 22:00
Crikey GB, you run over any chinamen lately?
The primary doesn't hold much oil so if a leak is detected it should be checked quickly. Must have been dry for a while to knacker the chain and chainwheel. The adjusting slipper would look a bit 2nd hand as well. This running dry would produce enough heat to do the damage. May I suggest my nylon slipper mod when your putting it all back together. The DeGroot one looks good.
Cheers
Title: Re: Primary needs
Post by: duTch on 21.07. 2018 22:34

 That's a bit crazy GB- surely you can't have forgotten to fill it after the rebuild- especially with indication of a leak, but you also Shirley would have noticed *that* much of a leak sooner.. *conf2*

 * sorry Shirley *smile*
Title: Re: Primary needs
Post by: Greybeard on 21.07. 2018 22:46
Crikey GB, you run over any chinamen lately?
The primary doesn't hold much oil so if a leak is detected it should be checked quickly. Must have been dry for a while to knacker the chain and chainwheel. The adjusting slipper would look a bit 2nd hand as well. This running dry would produce enough heat to do the damage. May I suggest my nylon slipper mod when your putting it all back together. The DeGroot one looks good.
Cheers
I don't know why it leaked so badly; I've never had the primary leak, (much) before. I reckon I did maybe 400 miles after I put oil in the case. The weather was very hot over that time; maybe that helped the oil escape. I had replaced the seal behind the clutch. I suspect the leak was from one or more of the case screws, (the oil has stained the case below the screws). I'll have to remember to apply sealant to the screw heads when I put it back on. When I opened it, the inside of the case was dry and coated in red, (ATF) dust! Nasty! The tensioner is scored but looks usable. The engine sprocket looks ok. The chain is deffo stretched/knacked.
Title: Re: Primary needs
Post by: Greybeard on 21.07. 2018 22:50
That's a bit crazy GB- surely you can't have forgotten to fill it after the rebuild- especially with indication of a leak, but you also Shirley would have noticed *that* much of a leak sooner.. *conf2*
I put oil in the case before I set off for South Wales. I saw some leakage but decided that it would last until I got home.
Title: Re: Primary needs
Post by: kiwipom on 21.07. 2018 23:05
hi G.B. ( dry as a witches tit ) never heard of that one before, maybe time to change to `Belt Drive clutch` cheers
Title: Re: Primary needs
Post by: Greybeard on 21.07. 2018 23:13
hi G.B. ( dry as a witches tit ) never heard of that one before,
It's a long time since that phrase has come into my head. It's a good one, eh?
Quote
maybe time to change to `Belt Drive clutch` cheers
Mm, maybe. I've just ordered a clutch sprocket/basket from De Groot. I've had no problems with the primary until this!
Title: Re: Primary needs
Post by: muskrat on 22.07. 2018 08:31
Unfortunately I don't think(that's normal) there's a belt drive setup for a plunger. BUT apparently a Notrun clutch will fit the plunger mainshaft and there's belt kits for them.
Cheers
Title: Re: Primary needs
Post by: Greybeard on 22.07. 2018 08:38
Unfortunately I don't think(that's normal) there's a belt drive setup for a plunger. BUT apparently a Notrun clutch will fit the plunger mainshaft and there's belt kits for them.
Cheers
How would you tension the belt?
Title: Re: Primary needs
Post by: RoyC on 22.07. 2018 08:59
hi G.B. ( dry as a witches tit ) never heard of that one before,
It's a long time since that phrase has come into my head. It's a good one, eh?
Quote
I've always said "flat as a witches tit" and dry as a kangaroos jock strap.
Title: Re: Primary needs
Post by: duTch on 22.07. 2018 09:10

 
Quote
  Unfortunately I don't think(that's normal) there's a belt drive setup for a plunger. BUT apparently a Notrun clutch will fit the plunger mainshaft and there's belt kits for them.
Cheers

 Not sure which (particular) bit isn't normal, but yes a Noturn clutch centre will fit the shaft, but the chainwheel diameter is too big, so physically won't fit and the ratio would be crap anyway...I had one to play with but it seems to have gone awol  *conf2*

 
Quote
....and there's belt kits for them...

 Belt drive kits for Plungers ??? yahoo, that'd be noithe.?....but.....$$$,$$$,$$$........ *eek*

Title: Re: Primary needs
Post by: muskrat on 22.07. 2018 20:56
G'day duTch.
Meaning there's a belt kit for Notrun clutches.The clutch on my Cafe is a Notrun diaphragm type with a center made for the s/a shaft. Haven't had to adjust it in 10 years of abuse.
GB, I'd suggest a new set of rollers as well.Cheers 
Title: Re: Primary needs
Post by: chaterlea25 on 22.07. 2018 21:58
Hi All,

Quote
Quote from: muskrat on Today at 08:31
 Unfortunately I don't think(that's normal) there's a belt drive setup for a plunger. BUT apparently a Notrun clutch will fit the plunger mainshaft and there's belt kits for them.
    Cheers
GB,
How would you tension the belt?

Look at RD's reply, *clap

https://www.a7a10.net/forum/index.php?topic=13218.0

John


Title: Re: Primary needs
Post by: duTch on 22.07. 2018 21:59
 
Quote
.....Meaning there's a belt kit for Notrun clutches.The clutch on my Cafe is a Notrun diaphragm type with a center made for the s/a shaft. .. .....

 Oh yeah got it. *doh*...I seem to recall using (or putting one in and not using), a Plunger mainshaft in my RoadRocket for some reason-   *dunno*
Title: Re: Primary needs
Post by: Greybeard on 23.07. 2018 11:30
https://www.a7a10.net/forum/index.php?topic=13218.0

I don't want to blow my own trumpet, but see those GB's on that engine. That's one of mine...honest!
Title: Re: Primary needs
Post by: morris on 23.07. 2018 12:03
https://www.a7a10.net/forum/index.php?topic=13218.0

I don't want to blow my own trumpet, but see those GB's on that engine. That's one of mine...honest!
Yeah right...  *whistle* and every car that's got "Morris" on the bonnet is mine...  *lol*
Title: Re: Primary needs
Post by: Greybeard on 23.07. 2018 12:52
https://www.a7a10.net/forum/index.php?topic=13218.0

I don't want to blow my own trumpet, but see those GB's on that engine. That's one of mine...honest!
Yeah right...  *whistle* and every car that's got "Morris" on the bonnet is mine...  *lol*

Really? I didn't know that! Did you play a Major or a Minor role in their design? I bet I know which university you attended.

https://en.wikipedia.org/wiki/Morris_Major
https://en.wikipedia.org/wiki/Morris_Minor
https://en.wikipedia.org/wiki/Morris_Oxford
Title: Re: Primary needs
Post by: Greybeard on 23.07. 2018 22:44
A BSAOC friend has offered to sell me a clutch basket. Just got to pick it up from Wiltshire. C&D have a new chain and clutch rollers. Things are looking up!
Title: Re: Primary needs
Post by: Greybeard on 27.07. 2018 23:18
I collected a good used clutch basket/sprocket today. The sprocket teeth look excellent. I have a new primary chain, new clutch rollers and a new cover gasket. I hope to attend next weekend's Hampshire BSAOC camp.
Before then I'm also going to change the back wheel bearings as they are slacker than I'd like.
Title: Re: Primary needs
Post by: duTch on 28.07. 2018 00:36
 
Quote
...Before then I'm also going to change the back wheel bearings as they are slacker than I'd like.

 I had a bugger of a time removing the old ones from a s/h hub I bought (the first one at least), resulted in making a tool for the job  *work*
Title: Re: Primary needs
Post by: muskrat on 28.07. 2018 02:04
G'day GB.
Nothing like an upcoming ride to put the pressure on with repairs. But you should be used to it by now.  *sarcastic*
Cheers
Title: Re: Primary needs
Post by: Greybeard on 28.07. 2018 20:36
I have been a busy boy today. I reassembled the primary drive using the used clutch crown that I bought from a BSAOC member. The replacement clutch, along with new rollers has less slack than the one I had before.

Musky, I took the chain tensioner off to decide if I wanted to modify it and attach a piece of  nylon chopping board the way you have. The rubbing area of the tensioner is hardened. I pondered sharpening a masonary bit to drill it but decided that my time is too short to muck about and possibly bugger the job up. Maybe another time!

I found some tiny fibre washers to put under the heads of the case screws. I think the oil leaked out, ( causing the damage) from the designated drain screw, that has a hole in the screw boss inside the case. So today, I got carried away and fitted fibre washers to all of the screws.


You can see my other updates from today in other forum headings.