Total Motorcycle Community Forums

All right Sevulturus, I understand now about this "bore" word, what and how to measure it.

Thank you very much you too for the help, Sevulturus.

Ok Johnj, I think I understand. You mean the measure that I need to know is from the interior of the cylinders, in orther to know the amount of consumed wall ( of the cylinder ). So, to compensate this consuming, I should choose the right set of rings that fill this consumed gap, for example 0.25mm ...

Thank you for your answer Jonhj. I still have a doubt about the bore. By bore you mean the hole/gap/space where the rings fit into, isn't it? Sorry to ask. I just want to be sure because english is not my mothertongue

Hi everyone!

I own a 1981 Yamaha XJ 650 (4KO). I'm having trouble to find the exact measures of the piston rings to this bike. I found a list of 4 different sizes. I these were never changed before in my bike. So, could someone help me to learn wich ones do I need?
There's a link bellow, in this ...