for info; asda petrol used in o/b motors has caused a few saltburn, marske boats to have had serious " gunging " effect on carbs, maybe effecting cars next? carb o/h by techs said water/additive ? in tanks at station due course? after o/h of 1st o/b non-asda petrol use -no problems, next 2 suffered due to thinking it was a 1-off & used asda petrol. this has been over a 6mth period. last problem, last week. o/b 10hp 4-stroke mercury, 20hp 4-stroke tohatsu. 30 hp , all newish engines.