What oil

[briand2]

OK, so what modern engine oil should I use in my A10

[DAVE BRADY]

Hi,

Is it just rebuilt with a clean sludge trap?  Then fit an external filter and use a full detergent 20/50 and a sump plate with a magnetic plug.

If not, then the sludge trap will have some sludge trapped in it an a detergent oil may mobilise it and damage may be caused so use a 'classic' oil with no detergent. A sump plate with a magnetic plug is still a good idea as well as the external filter.

Dave.

[briand2]

Thanks Dave, I have not re-built engine, mostly cosmetic work, where is the sludge trap?

[DAVE BRADY]

Hi,

If you look at either end of the crank you will see a slotted plug. The sludge trap is behind them and takes the form of a removable tube.  To remove it you will also have to remove the flywheel bolt nearest to the big ends.
Removal can be a pain as things get quite settled over the years.
There a few threads in this forum about this so have search and if you do not already have a workshop manual it is a good idea to get one.

Dave. 

[AltcarBob]

If you ask 5 experts about what oil to use you will get 6 different answers. Personally I have used Smith & Allan mineral 20w50 for quite a few years and none of my classic machines have blown up yet.

https://www.ebay.co.uk/itm/254963983047?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=sedlIGgKSai&sssrc=4429486&ssuid=&var=&widget_ver=artemis&media=COPY

[rhyatt]

What does the original owners manual tell you ?
Possibly sae 40 or 50 for summer and sae 30 or 40 for winter.
These engines were made during a period of oil stability when everything ran on only 3 or 4 oils available, clearances and tolerances were made by the factory allowing for these available oils.
I use monograde oils in my classics for these reasons.
Bearing in mind the mileages these classic bikes do now , compared to 50 years ago it will never get dirty.

[DAVE BRADY]

Hi,

There was very little change to big ends and TS bush from the first A10 to the last A65.
Oil recommendations went from mono-grades to a combination depending on what was available where the bikes were sold to multi-grades in the latter days.
Oil in low mileage bikes may not get dirty but it is still best to change it regularly due to possible contamination from condensation and other degrading affects from leaving a used oil sitting for long periods of time.
My preference for a modern 20/50 has been over a long period and high mileage with two bikes covering over 250,000 miles between them.

Dave.