Jump to content

Oil Ratio


Recommended Posts

Hi sorry to sound dumb

Just picked up a greeves Scottish 24 tcs

Could anyone let me know the optimum 2 stroke oil to use in this bike and what recommended ratio

Cheers in advance


Edited by mjc477
  • Like 1
Link to comment
Share on other sites



Originally these old air cooled engines used a SAE 40 or SAE 50 2T oil because of the large piston / bore clearances. Modern synthetic 2T oils tend to be much thinner (SAE 20 to SAE 30) but have high thin film strength.

Castrol A747 as above is a good high viscosity oil as is Shell VSX. Bardahl do a high viscosity 2T oil but its about £30 a litre. I would be inclined to use the Castrol at about 30 or 40:1 but you could use something much cheaper like gulf pride 2T (less than £10 for 5L) at 24:1

You could use any good quality synthetic oils at leaner than 40:1, your bike won't seize but it will rattle a bit as these oils are meant for close tolerance water cooled engines.

A747 is meant for very high performance water cooled engines but it works well in anything.

Link to comment
Share on other sites


i started running my 1958 iron barrelled scottish on 40.1 mix with modern synthetic oil, on the advice of the experts , great in the sections but on the road between sections it locked up 4 times it freed of after cooling down and i was able to finish the event, i asked the greeves riders club for help and the answer was to use a good quality oil at 25.1 mix, since then the old engine has been fine so i will stick to the advice of the greeves guys. will. i

Link to comment
Share on other sites


Ok just in case anyone's interested....

I brought some castrol a747

Mixed it 30-1. 165ml to 5ltrs

Was all ok..perfect on the road and ok on a little 5-10 mins green lane..

I'll stick with this and see what occurs

Thanks again

Link to comment
Share on other sites


aawil #4.

Thanks for pointing that out and I will amend my earlier advice and I now feel a bit daft. For some reason I had thought MJC 477s bike had an alloy barrel with steel / CI liner and roadwork never entered my head. The bore of a barrel of all cast iron does not expand sufficiently compared to the piston on sustained road running. More oil is needed to conduct the heat out of the piston. I would now not advise 40:1 but the 30:1 on A747 he has chosen should be fine.

Interesting to see the Greeves club advise similar to my ratio advise for gulf pride 2t, a good quality old fashioned mineral oil.

Link to comment
Share on other sites


Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...