thank you all , will this stuff do then ??? http://www.millersoils.co.uk/products/superfleet-sd-10w30/501
mrsmelly, the previous owner had the boat from new and from day one used the recommended oil in the manual, 10w/30 api cc, it also happens that he used the barrus shire brand, he also knew that i would not use the boat more than 250 hours when i told him about myself and my plans for the next 12 months last august, (the recommended time for an oil change is 250 hours or twelve months which ever comes first) i have only used the engine approximately 200 hours , 4-5 hours every week end since including all of winter and he had done the last oil change about this time last year , so thought it good form to follow the manual and use the same oil,. Ok i now understand that it doesn't have to be Barrus Shire brand oil but at least a good quality oil of the same viscosity / api spec, surely.