So i am looking into buying a Kawasaki 650 or a yahama superjet 650 in the early 90's. which would be considered a beter buy in terms of the following: reliability, performance, and availability of mods
I am assuming you are referring to a stand up model? Both are great and you cannot go wrong with either one. I have a Kawasaki stand up. It is a 96' 750 SXI and I love it. It has been very reliable and has been through many waters from fresh water lakes to the ocean during storm conditions with very high surf. Yamaha is also good though. If my memory serves me correctly, Kawasaki's have a little bit higher top speed that the Yamaha's do but the Yamaha's have better stability which is why most racers and stunt guys go with Yamaha. But either way you go, I think you will be happy.