Iown a 2000 kx 125 and looking for a new barrel and wanted to know which years model are interchangable.Is it possible to put a 2 piece power valve from a later model into a three piece cylinder. :think:
You can mix and match cylinders but there are some subtle differences in the power valves. Your original power valves may not bottom properly in the other years cylinder and you may need to do some minor machining to the castings in the power valve area of the cylinder. If you don't want to machine the cyclinder then you will have to buy the power valves to suit that model year of cylinder which is expensive.
I had what I thought was an '01 cylinder on a 2001 KX125 which was trashed, when I bought a new '01 cylinder it was different to the trashed one! I managed to compare the old cylinder against the '01 and an '02 & '03 cylinders and it was different from them all in the power valve casting areas (I still don't know what year the old cylinder was). To save buying a new set of power valves I had some very minor machining done to the webbing on the sides of the cylinder where the PV fits in and then the PV fitted perfectly, the webbing prevented the PV stop from bottoming into the correct spot. it can easily be done and you get the benifits of the later model port timings.