I bought a 06 YFZ from someone who obviously did not change the oil in his quad. I didn't check before I bought, but soon found out it was a quart low on oil!! It didn't smoke when I bought it but, after changing oil and doing some mods to it, it has started smoking. I torn it down today and have scoring on the cyclinder walls and piston pin/rod piting. Also I checked the piston ring end gaps and had 2.58 mm on 1st ring and 2.63 on second ring. That seems way out of wack so I didn't measure oil scapers. There was a lot of carbon buildup on the piston, valves/head, and exhaust chamber. I have a service manual and was wondering what tools are needed to split case halves? And were can I buy them? I seems like the manual lists a lot of specailzed tools. What do I really need? I guess I will buy a HOT RODS crank/rod and Athena 480 big bore kit. Any ideas or sugustions? I will also be doing the oil mod as well since I have the engine torn down.