^This. I can not speak for the R1 but i am on my 3rd R6 and not because of problems i just upgraded through the years too newer bikes. In MY OPINION the yamaha power plant is very reliable as long as the maintenance has been kept up, i would look at the basics before buying such as the oil and things and then obviously do the normal checks. Check the front stay make sure there are no cracks or the bolts are not loose from wheelies and such and also i would check and make sure tire weights and things of that nature are in the proper place and have not been knocked off from abuse. Once again in MY OPINION you can not go wrong with a Yamaha as long as it has been treated decent. PS. i ragged out my 01 with wheelies and everything else and in the end yes the body and all parts were in not so good shape but the motor never missed a beat!!
Is this your first gun?? I am a huge gun person but if this is your first, do yourself a favor and go with someone and learn the basics... just going out and tearing "shit" up is fun, but you will be happier in the end when you know the correct way to clean and service your firearm and the basics of shooting it.