The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: ShaunMac on 25.03. 2013 13:18

Title: Dynamo chain slack?
Post by: ShaunMac on 25.03. 2013 13:18
Hi guys,

Took the timing cover off today and glad I did as the grease that was in with the dynamo chain was rather contaminated.
Q1 - Is it meant to be packed with grease?
Q2 - Is there a way of adjusting the chain as it is very loose and appears to have been catching the casing.
Q3 - Some oil came out. I presume this would just be residual from the pump area or does it mean I've got a leak on the oil pump?

Thanks,
Shaun
Title: Re: Dynamo chain slack?
Post by: ShaunMac on 25.03. 2013 13:57
A bit of searching and the Haynes has given me the answers.
Thanks
Title: Re: Dynamo chain slack?
Post by: stu.andrews on 25.03. 2013 14:04
Hi
When adjusting the dynamo chain be very careful as, when the dynamo strap is tightened, this will slightly turn the dynamo, thereby tightening the chain even more. This will then ruin the chain, sprockets & dynamo bearing on the drive side. 'Tis a bit of trial & error & watch for tight spots in the chain. A semi liquid grease is good as this will thin further when the engine gets hot.
Title: Re: Dynamo chain slack?
Post by: ShaunMac on 25.03. 2013 16:13
Thanks. I've got 1/4 inch slack as a figure. At the moment it's about 1 1/2 which is why it's been cutting in.
Title: Re: Dynamo chain slack?
Post by: Goldy on 25.03. 2013 17:44
Shaun
If you do a search on the forum you will find info about the types and amount of grease.
The bottom chamber will be full of oil when you remove the cover.
All the best Goldy
Title: Re: Dynamo chain slack?
Post by: chicago on 25.03. 2013 23:54
Hi fella, I picked up a really handy tip off the forum when replacing the grease (muskrats or bsa bills idea I think ?) put the new grease in a Jiffy bag, put it in the freezer overnight and before your about to put the timing cover back on get the grease out of the freezer, snip the corner of the bag and pipe the grease in, that way the grease doesn't just run straight onto the floor and on your new gasket. I made up my own grease (slightly runny) by mixing straight 40 oil and grease. I think if you use standard grease (ie thick) the dynamo chain cuts a track thru it and doesn't lubricate the chain. All the best, Chicago.
Title: Re: Dynamo chain slack?
Post by: ShaunMac on 26.03. 2013 08:12
Cracking idea! I used to hate filling power narrow beds with grease as it always slowly crept everywhere!
 *smile*
Title: Re: Dynamo chain slack?
Post by: bsa-bill on 26.03. 2013 09:48
good idea, unfortunately not mine must be Musky

Both my bikes on belt drive, now I do know a fella that drove a small Cat skid shovel who greased the alternator/fan belt to stop it squealing, it certainly did  *eek*
Title: Re: Dynamo chain slack?
Post by: muskrat on 26.03. 2013 11:57
 Not mine either. ???? Had toothed belts on both mine for a few years now. Back when running a chain I just used common old black (or was it red) grease. Went on easy and when hot it softened enough to cover the chain.
Cheers
Title: Re: Dynamo chain slack?
Post by: chicago on 26.03. 2013 12:17
Hi bill, muskrat. Memory like a sieve me  *conf*,sure it was on here I read about freezing the grease. I've converted to a srm toothed belt as well but was told by the guy from srm to still use grease as it helped to keep the belt from over heating ???. All the best fella's. Chicago
Title: Re: Dynamo chain slack?
Post by: bsa-bill on 26.03. 2013 14:05
Quote
guy from srm to still use grease as it helped to keep the belt from over heating

Well not as silly as it may sound with a toothed belt, I know my chamber filled with oil due to a wrongly orientated bush scroll (posh way of saying I screwed up) and the belt ran just fine with oil coming out of the dynamo mounting flange.
Th guy I referred was lubing a vbelt ? 
Title: Re: Dynamo chain slack?
Post by: ShaunMac on 26.03. 2013 16:10
Well I got the dyno off today and cleaned all the contaminated grease.
The dyno has had a bad lick of paint at some time so cleaned that up and primed it for a fresh coating.
The end cap has been damaged at some time so I need to replace it.
Any recommended suppliers?
Also, I've seen a rubber cap for over the wires where they go into the dyno. Do these fit?

Cheers,
Shaun
Title: Re: Dynamo chain slack?
Post by: bsa-bill on 26.03. 2013 16:26
Quote
Also, I've seen a rubber cap for over the wires where they go into the dyno. Do these fit?

yes they pull over the fancy shaped insulating piece that hold the wires, sorry can't recall where I got mine but got both the rubber and the insulator bit same place
What do you call that stuff again it's not mica is it
Title: Re: Dynamo chain slack?
Post by: Topdad on 27.03. 2013 14:47
That'll be tufnell ,Bill regards bobH.
Title: Re: Dynamo chain slack?
Post by: a101960 on 27.03. 2013 16:21
Quote
What do you call that stuff again it's not mica is it
Bill, it's called paxoline
Title: Re: Dynamo chain slack?
Post by: bsa-bill on 27.03. 2013 16:26
Cheers lads
Title: Re: Dynamo chain slack?
Post by: Gerry on 31.03. 2013 14:25
Hi Guys, I am using Moreys grease on my dynamo chain, don't know what grade it is as I have had it for years and the paper label disappeared  years ago, but if you put your finger in the grease and raise it vertically you get a string of grease about a metre long before it breaks. It sticks to gears and chains like s*~t to a blanket. As for greasing a timing belt, what would you use, as ordinary grease will perish rubber quicker than anything. Unless the belt is silicone rubber of course? Gerry
Title: Re: Dynamo chain slack?
Post by: wilko on 01.04. 2013 00:53
There are organic type greases used in machinery that are for food production. They are used on grape harvesters where you dont want your bottle of plonk contaminated!
Title: Re: Dynamo chain slack?
Post by: a10gf on 01.04. 2013 01:08
Also maybe check the chain for uneven tension, ie rotate the engine and check chain at different points.
(and once I managed to do a ghastly mistake when doing just that. I'll tell the story one day *red* ...hint: remove both sparkplugs before trying to rotate engine...)
Title: Re: Dynamo chain slack?
Post by: muskrat on 01.04. 2013 04:42
Ha, yep done that too e. Winding crank over on the racer by spanner on the crank nut. Never did find that spanner. Next lunar mission might.
Cheers
Title: Re: Dynamo chain slack?
Post by: bsa-bill on 01.04. 2013 10:16
Quote
Unless the belt is silicone rubber of course? Gerry

just exactly what they are I think, SRM one is steel re-enforced red or clear type synthetic material - seem pretty tough.

Quote
Next lunar mission might.

along with that grease gun Capt Janeway let slip ( not only OT but sexist too ) *smiley4*