The Marston Sunbeam Club & Register Forum

General Category => Technical Discussion Forum => Topic started by: Upperstoker on May 14, 2017, 09:21:51 PM

Title: Oil Level
Post by: Upperstoker on May 14, 2017, 09:21:51 PM
I have a newly acquired 1935 model 9 and am fitting a new '0' ring primary chain. It is meant to be self lubricating so I was thinking about using a spray lubricant at suitable intervals and not running the case with oil. Appreciate views on this approach or if an oil bath is preferred what level should the primary chain case be filled to?
Title: Re: Oil Level
Post by: Davetom on May 15, 2017, 07:34:25 AM
Hi, from what I gather, primary chains get too hot in enclosed chain cases if just run with chain lube . I have a friend with a Matchless that does that but he rarely rides more than 30 mins from his house. I use red Automatic Transmission Fluid in my twenties Model 6, just enough to wet the back of the chain ( 70mls in my case, but your cases will be different )
Title: Re: Oil Level
Post by: Upperstoker on May 15, 2017, 09:11:07 AM
Thanks for the advise.
I think the previous owner of the bike might have run with red fluid judging from the inside of the case.
Just need to find out how much fluid I should be using as I am not able to see the level through the inpection cover?
Title: Re: Oil Level
Post by: Davetom on May 15, 2017, 10:48:53 AM
Fill it til the back of the lower chain run is just touching the surface. If you let it settle then turn the engine over a few times, you should feel oil on the back of the top chain run, felt through the inspection cover
Title: Re: Oil Level
Post by: VicYouel on May 15, 2017, 11:34:01 AM
I may be wrong but I have always assumed that clutches using cork material should be run in oil. If the oil is too thick it will drag and probably slip so a very thin oil should be used. I prefer a skinny multigrade or even telefork oil. My experience in  this respect is mainly with pre war Triumphs.

However if modern friction material is being used in the clutch the presence of oil may have adverse effects.
Vic



Title: Re: Oil Level
Post by: Upperstoker on May 15, 2017, 12:17:50 PM
Thanks. 
Not sure what matterials are in the clutch but does not sound as if I will need much fluid to run the chain in.
Title: Re: Oil Level
Post by: iansoady on May 15, 2017, 04:01:46 PM
I can't really see that 70ml of oil can have any appreciable cooling effect. I appreciate that primary chains run much faster than secondaries, but even so the power being put through them (even on a 90) isn't much by today's standards.
Title: Re: Oil Level
Post by: Davetom on May 15, 2017, 05:24:44 PM
Hi Ian, I don't think it's so much a cooling effect, more a 'preventing getting hot' effect if that makes sense ?!. Constantly having a light splash of oil is preferable for me as I think that spray grease gets flung off, and doesn't return as easily, whereas the oil just collects and gets re-used ? The ATF fluid is compatible with clutch corks too, not sure how the corks fare with chain grease ?
I led the Coventry to Brighton run last weekend, rode the 350 mile round trip without any loss of clutch or grab, despite heavy Saturday afternoon traffic through Bracknell and Henley on Thames
Title: Re: Oil Level
Post by: phutton on May 17, 2017, 01:39:24 PM
The oil mist generated helps keep the clutch components lubricated, and helps smooth operation.

Paul