Correct oil for Ransom Marquis
I have a Ransom Marquis bought new in 1975 and have always used Castrol GTX . I have recently tried to buy some more only to find that GTX is now partly synthetic. The mower is fitted with the sloper engine. I have been told that synthetic oil is not suitable for old engines. Has anybody any suggestions?
There's an old adage - any oil is better than no oil!
1975 - so do you have one of the last BSA/Villiers F12 "Sloper" engines or a Briggs and Stratton.
If it's a Briggs the only recommendation for UK summer use is a straight high detergent SAE 30 oil. If this is not available a 10/30 is permissible at the expense of a possible increase in consumption .
If you have a Sloper one of the original specified oils was the first generation GTX. I doubt if any harm will come from using a semi synthetic but I wouldn't mix the two. So if you wish to use it I would get the engine hot and drain all the existing oil before using the new brew.
I run several Slopers, all on SAE30 - controls consumption with no ill effects!
Thanks for the advice. The machine was one of the last slopers. I think I originally used Castrol XL before GTX was available.
"Thanks for the advice. The machine was one of the last slopers. I think I originally used Castrol XL before GTX was available."
Possibly but my manual dated 1970 mentions both GTX and XL plus Catrolite for cold weather running. So I think it safe to say that GTX was around when your machine was made.