Which oil to use for 1951 Airone?

Hi folks,Im shortly going to put a 1951 Airone Sport on the road after a long time in storage. Whats the current thinking on oil,is it best to stick to tradition and use straight 30 and 40 or use 20/50 multigrade such as Castrol XL?

I run a 65 Stornello and run it on straight 40 as per the recommendation of the factory manual. I tend to think the designers know best.
If you haven’t found it already, it might be worth your while joining the Google Guzzi singles group, there are a lot of knowledgeable owners in the group.

Many thanks Don,you cant beat experience and Ill have a look at the Google singles group web site.
Best wishes,Eddie

Important you use a Classic low detergent oil on any older engine without full flow filtration, otherwise wear particles become encapsulated but never trapped, instead of dropping out of harms way. Planning to change mine on Airone to CC rated Morris Golden Film 20/50. Their straight 40 made my Velo difficult to kick over mid winter especially if wet sumping.

Worth remembering that modern oils including multi-grades were not around when such bikes were built so manufacturers recommendations were limited.


Thanks Richard,the oil I was thinking of using is Castrol Classic XL20/50 which is for older engines,Im using it at present in a Triumph T100r engine in a Tricati with good results,different engines I know but Castrols blurb reckons its good for 1950s`engines and is CC rated. I expect it will come down to personal preference in the end.
Many thanks for your input,Eddie.c

The other big consideration for choice of oil is how it affects the clutch. I used to run my T140 0n Halfords Classic and had troubles with the plates sticking, then changed to Morris 20/50 designed for motorcycles and it is a lot better.
I’m not sure if the Airone runs a wet clutch?