BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: mo goldie on 28 February, 2020, 00:41:19

Title: Dynamo leak on RGS-R
Post by: mo goldie on 28 February, 2020, 00:41:19
Hi has anyone got a clue of how to stop oil/grease coming out the Dynamo cork gasket..... I have fitted a SRM Belt drive
so it has No chain now and they recommend that you fill most of the case where the belt run with Grease now I have had the case both inner and outer off and done what they say but as soon as I have started the bike up do it run out with the grease, so is they anyway or anything I am doing wrong I pushed the Dynamo as hard up against the back of the case where the cork gasket is and then done up the clamp but it still leaks out from behind the Dynamo its driving me crazy.......just need some help please.

Thanks in advance..

Maurice     
Title: Re: Dynamo leak on RGS-R
Post by: chaz on 28 February, 2020, 00:52:15
Mastic or you could tap a hole and fit a plug.
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 28 February, 2020, 08:35:52
Hi Maurice,

Did the grease leak out when you ran a chain to drive the dynamo and if not, have you put more grease in than before?
When the engine gets hot a bit of pressure will build up and will have to be released somewhere and the cork gasket will be the weakest point.  I would suggest putting a lot less grease in.  When warm the grease will accumulate at the bottom of the case and then be picked up by the belt as it would have been the with the chain.  Too thick a high melting point grease will just be thrown off the belt and stick to case. Looking at an alternative belt drive supplier, they say their's can be run in grease but do not imply that it is a necessity and can be run dry.  It is my understanding that these belts are intended to run dry as in a primary belt drive so why do they need a lubricant - cooling perhaps?
 

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 28 February, 2020, 09:54:52
Hi Dave, I did not run the bike with a chain as I was having to build a lot of it up and that was just one more job that I done to it, I will try running a lot less grease in the case and see how that go`s someone suggested that the cork if i was to use silicon on it that also might help...at this stage anything is worth a try.

Maurice. 
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 28 February, 2020, 10:14:26
Hi Maurice,

The silicon may help.  But let us know if less grease helps as it may be useful to others.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: JulianS on 28 February, 2020, 10:29:33
Sometimes the thin sealing washer or cork between the back of the large sprocket/pulley and the inner timing cover breaks up allowing some oil and a bit of pressure into the dynamo compartment which can cause a leak from the dynamo cork.
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 28 February, 2020, 14:32:11
Over the years I have known several people leave this cork washer out completely as they did not know what it was for.
There is does not seem to be much reference to it and as it is quite thick before it is squashed behind the sprocket/pulley it almost looks like it is too thick.
The other washer that is sometimes overlooked is the one that goes on the third oil pump stud.  Leaving this out results in the pump being distorted when the nut is tightened up.  I measured this gap once with the pump on the two main studs only and it was over 0.007".  Not a lot but enough to cause problems.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: Trev on 28 February, 2020, 17:09:13
Unfortunately I had this problem once many years ago. It was caused by a breathing problem which allowed pressure to build up and force the grease out. The engine was subsequently rebuilt not long after and that cured the problem. First thing I would check though is the cork disc for failure or wear. Despite  what SRM might advocate I have a Manortech DVR2 regulator and belt drive conversion and I have never greased mine. Its not needed. I would take some of what SRM say with a pinch of salt! Bear in mind if they build an engine for you they say the warranty is invalidated if you fit an oil filter. Really!!!!
Title: Re: Dynamo leak on RGS-R
Post by: Editor on 29 February, 2020, 10:16:57
Regarding the reason for SRM recommending grease, my mate Geoff fitted one of their conversions years ago, dry, as there was no mention of grease by SRM or anyone else. His belt broke recently, it had cracked up around the edges and the teeth had been worn away somewhat as well. He bought a new belt from SRM and was told to apply grease.
So, it sounds like grease is necessary but purely to give the teeth surfaces a bit of lube, so I wouldnt fill the space as you do with the chain.
Title: Re: Dynamo leak on RGS-R
Post by: Bess on 29 February, 2020, 11:00:23
Hi,
    Maybe worth trying these:

https://www.beltingonline.com/at5-gen-iii-synchroflex-timing-belts-4594

https://www.beltingonline.com/images/PDF/Syn.pdf

This timing belt 'GEN III' is temperature resistant up to 100C, no need to grease and a fraction of the cost from well know suppliers.

Best wishes...
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 29 February, 2020, 11:38:19
How long are these belts supposed to last?  Most belt suppliers stock the right grade of belt at a very competitive price and some just cut off the width you need from a long tube.
I have found a 'V' belt just as good in many ways.  Running an Alton on my wife's A10 with a 'V' belt was much better than a chain and whilst the Alton had quite a resistance to rotation the belt would last a reasonable time and they are cheap.  If necessary a belt could be replaced in about 10 minutes - always carry a spare.   I tried the toothed belt similar to the one being discussed and it did not last very long at all so the 'V' belt was recommissioned.  This regime lasted 14 years and many thousands of miles until the Alton gave up.  The latest replacement Alton uses different magnets so it spins about as easily as a dynamo.
With less resistance to overcome the 'V' belts will be as good as anything.  However, one advantage of the toothed belt systems is the increased speed of the dynamo giving a more useful output at lower engine revs.
Interestingly I think SRM suggest carrying a spare belt just in case.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: Bess on 29 February, 2020, 13:18:33
Hi,

  Suppliers say, "Life expectancy is estimated at 10 years or 30,000 miles".

Best wishes...
Title: Re: Dynamo leak on RGS-R
Post by: bikerbob on 29 February, 2020, 14:18:04
Over the years I have run both V belt drive and Tooth belt drive the advantage with the tooth belt system and the one I am at present using on my A7 was supplied by Dyamo Regulators is that you get increased charging at lower revs, With the original chain drive you had to be  running over 30mph to get a charge with the headlight on with the tooth belt I can show a charge with headlght on at just under 30mph. The disadvatage with V belt was you had to keep it quite tight or it would slip I had to adjust mine on a yerarly basis  also you did not get the increase in the charge rate. I have had my tooth belt system now with no problems for about 5 years and no grease in the compartment. It is possible that the reason for early failure of the toothed belt could be tension too tight when set up not allowing for the tension increase when hot I tend to run mine sllightly on the slack side.
Title: Re: Dynamo leak on RGS-R
Post by: idie on 29 February, 2020, 21:30:07
Why on earth do you want to run a belt drive in grease. My son and I have been using Dynamo Regulators Ltd belt drive in our Shooting Stars for years without grease.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 16 March, 2020, 18:20:09
hi well here we go with an update, first I replaced the cork gasket behind the larger of the two pulleys and sealed the cork gasket on the Dynamo, went out for a 30 mile ride today got back to find there was some oil over my nice shiny casing which was not good to see that, it was oil and not grease as I put not a lot in there at all this time, so I think JulianS said about the Dynamo compartment was being pressurised which I think could be right the only thing is why or how do you stop this ? I don't want to go down the root of drilling a hole in the case to vent into the oil Breather pipe which I put on the Engine side when that started to leak oil out of there but since that now is vented to Atmosphere and I have had no problem with at all since I done that....the engine has now done 450 miles since its rebuild so the bottom piston rings must be bedded in by now......but don't know what else to do ?

has anyone got any other Ideas please   

cheers Maurice   
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 16 March, 2020, 18:42:08
Hi Maurice,

Have you recently replaced the idler gear bushes?  They both look identical but I believe they have the oil groove going in opposite ways.  The outer one is spiralled to take oil back in to the engine. If an inner bush is put in the outer position it will push oil in to the dynamo drive area.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 16 March, 2020, 20:09:24
Hi Dave that is a really good Question as I did not put the engine together so that's one thing I am not sure about so the next time I get a chance I will strip the two cases and look at that.....   
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 21 March, 2020, 22:56:18
Hi,


here is the update as of today I took off the outer and inner cases and as i took the outer case off it there was quite a lot of oil in the Dynamo compartment so on removing the larger wheel and taking off the belt I then took off the inner case and had a look at the bush which was the right way round as the spiral was going to the left inward and as the idler rotate anti clockwise that should be taken the oil back into the engine, so I took the bush out as it was a bit of play on the shaft.....as I have pri ordered a new one which should be on its way from D/F next week so I can check if there is a lot of ware in the bush or Not.....so we will see if it has or not............if not were do I go next ?

Cheers Maurice
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 22 March, 2020, 07:52:40
Hi Maurice,

This must be a pain in the neck for you.  Some basic ideas that may or may not help.
450 miles may not be enough for complete bedding in of the rings so possibly a contribution there.
Is there any oil coming from the timed breather - indicating a crankcase pressure issue -rings not yet run in, breather not working properly- can you feel pressure coming out of the breather hole?
Are the timing cover gaskets sealing properly - especially the outer one which is quite narrow towards the bottom of the chain run - the face it sits on is also quite narrow.
If your engine still has the timing side bush you could try running it for a minute with the timing cover off - if every thing is clean to start with you may see if anything is getting through the bush in question.  Beware though it can get a bit oily.
I share your frustration.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 23 March, 2020, 00:12:56
Hi Dave

Yes it is a pain as had them cases off now about 4 times :(

well there is no oil at all coming out of the breather....and yes you can feel a small amount of pressure coming out but not a lot, and as far as I know all gaskets seem to be sealing ok.....I have always used wellseal but this time I am going to use a  9911 RTV Silicone sealant Gasket compound as well to make sure they seal good,

Thank for your advice dave been a great help, well when I get the bush and the new gaskets come I will try it all out and see how it go`s and let you know

That's if I don't have to stay in as I could be one of the ones that get the Letter to stay in for 12 weeks............I would go Nut`s I think if I could not get out on my Bike`s :-(   
Title: Re: Dynamo leak on RGS-R
Post by: TTJOHN on 23 March, 2020, 09:20:51
Should have bought a kit from Dynamo reg ltd, in Fareham, Hant's, Mikes belt conversions, 15 mm toothed belt, doesn't need lubrication, they are very highly recommended, I have them on all of my twins, very efficient.

My2p TTJohn
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 23 March, 2020, 20:05:02
Hi TTjohn, I think you have Not looking at the whole thing..it`s not that is is a SRM belt driven Dynamo conversion it`s the fact that the Dynamo compartment is getting and a oil build up as I did not put loads of Grease in there this time anyway, but oil is filling up that part of the compartment properly down to oil coming through the cam pinion bush.............well we shell see if it is due to ware on the outer bush letting the oil through it.............that's if I get it together and able to take her out to try with all what is going on at the moment if you know what I mean............ Keep safe all of you.

Cheers Maurice   
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 26 March, 2020, 22:38:25
Hi, well as of today I have her back Together with a new bush fitted from D/F along with new Gaskets Etc, the thing is do anyone know what way the scroll run`s on the bush as the one what was in there looking from the outer case side starts from the left inwards and the New one starts from the right inwards........so have I found the reason Now or Not why it was pressurising and putting oil into the Dynamo compartment.........well I wont Know I don`t think now until we can get back on the road with whats going on at the moment and I can get out and try her, I have had it running up for about 10 mins and nothing yet fingers crossed.......but as I say do anyone know of the way the scroll go`s as the new one do go the other way than the one what was in there ?

Cheers Maurice

Stay safe everyone.....oh and stay in doors to help us all to carry on riding in the future .............. unless you have to go out that is 
Title: Re: Dynamo leak on RGS-R
Post by: JulianS on 27 March, 2020, 10:31:57
These photos may help.

The first from an old as found inner cover.

The second fitted around 12 years ago and recently replaced when I fitted a new idler spindle.

Note the difference in scroll depth.

The spindle needs to be a good fit for the scroll to be really effective and you do need the cork or felt seal between the bush and back of the large dynamo sprocket. Neither will fully succeed if the oil pressure in the engine is too high.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 27 March, 2020, 13:10:31
Thanks Julians

they have both got the Scroll`s going the same way as the new one I have just fitted and they look to have the same Depth as the new one too, as for the one I replaced it had a very shallow Scroll and it was going the other way.....so I will keep my fingers crossed that it might be ok Now............we will see, and I will keep everyone updated as soon as we can go out to try things......back on the road again :-)

Cheers Maurice
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 05 April, 2020, 22:48:25
Hi everyone

well here is an update, yesterday I had to go out to the Pharmacy to pick up some meds so I thought are here is a chance to try out the BSA........ended up doing about 20 miles so the first thing was to check everything out :-(

well on looking at the underside and the front of the Dynamo I could see a trickle of oil coming down from the back of the Dynamo and running down under the sump so guess what that means it is still leaking oil into the Dynamo compartment..........
so Now I am at my wits end as I have done everything I can think of so lost for words Now...............other that a Nightmare :-(

Maurice   
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 06 April, 2020, 08:12:09
Hi Maurice,

Sorry to hear you are still having this problem.  So a bit of sideways thinking.  All the possible parts, bush, cork washer and spindle  are good fit.
Is there any damage to the centre boss where one of the screws goes?  Sometimes a slack chain will damage this by scoring grooves.  It is possible that these go through to the screw and oil could be finding its way through especially if there is a lot of crankcase pressure.  Also, as mentioned by Julian, too much crankcase pressure could overcome the seal of the cork washer.
If there is too much crankcase pressure it is usually caused by failure of the piston rings to seal or the timed breather is not functioning or is blocked/partially blocked.
Check the breather 'top hat' on the end of the cam - there should be absolutely no play.  See if you can feel the pressure releasing from the breather hole at the back of the crankcase.   

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 06 April, 2020, 21:21:22
Hi Dave

well when I got the kit it came with a felt sealing washer behind the large belt pulley wheel and I thought about putting on the cork one on which I have got a new one from D/F but it would not fit behind the pulley wheel as it is to thick and I did not want to force the pulley on to it, the Breather yes is a very good fit with No play and there is very little pressure that I can feel coming out of the crankcase breather, I did check the inner case for any damage that the chain might have done but there was only one bit which had been hit by the chain which was not bad at all so everything seems to be ok. it make me wonder if I should have put that cork washer on but I think as it would have been hard up against the pulley and the back of the pulley wheel I thought it might have got damaged as soon as I started the engine...but how knows.......Maybe I might take the outer case off yet again and try putting the cock one on and give it a try.....what else to do I can`t think of anything......oh the bike has now covered 490 miles so I would think them piston rings are getting a bit bedded in and still staying under the 4,000 rev range.

Thanks maurice
Title: Re: Dynamo leak on RGS-R
Post by: DAVE BRADY on 08 April, 2020, 21:54:03
Hi Maurice,

It is surprising how much a cork washer will crush.  It deforms to fit the back of the pulley and the shape of the end of the bush and the casing making a very good seal.  So this could be the answer.  Put some grease on the cork washer and it should be fine.  Good luck.

Dave.
Title: Re: Dynamo leak on RGS-R
Post by: mo goldie on 08 April, 2020, 22:40:46
Thanks Dave it sounds the only next thing I can do so over the next week I think that is what I will try........so watch this space as they say......stay safe

Maurice