Recommended Oil

I have a 2007 Yamaha R1. The guy that had the bike before me said that all the bike has had ran through it is 20/50 synthetic. The owners manual says only to use either 10/30 or 20/40. The last oil change on the bike was done by him at 4,000 miles. I just rolled 6,000 miles so i was wondering what kind of oil should i put it in when i change the oil? Thanks for your input.

I have a 2007 Yamaha R1. The guy that had the bike before me said that all the bike has had ran through it is 20/50 synthetic. The owners manual says only to use either 10/30 or 20/40. The last oil change on the bike was done by him at 4,000 miles. I just rolled 6,000 miles so i was wondering what kind of oil should i put it in when i change the oil? Thanks for your input. Repsol Moto 4T Racing Synthetic Oil - 10W30

I have a 2007 Yamaha R1. The guy that had the bike before me said that all the bike has had ran through it is 20/50 synthetic. The owners manual says only to use either 10/30 or 20/40. The last oil change on the bike was done by him at 4,000 miles. I just rolled 6,000 miles so i was wondering what kind of oil should i put it in when i change the oil? Thanks for your input. that 4T synthetic oil is spendy, bout 8 bucks a quart. I dont know if if makes any difference. but I use yamalube oil from my dealership. works fine and I have 23, 000 miles on the bike all with that oil, and I beat the sh!t out of my bike lol