The differences are minimal and are not even visible. If I recall right the flow rate is slightly better with the 140 so I have always used them in everything that said a 141. I have been doing this since 2011 on all the carb bikes. Never had an issue and any troubles are not from this but due to age and heavy use. These bikes are ridden almost every weekend for more years than I can remember. More than anything keep the oil clean and change it often.