After that run I noticed that the bike had losts its power, so I decided to do a top end rebuild. I disassembled the top end and found that the right side vavle was broken and the left one was not even there. The center valve was de only one working properly.
I went online and found a pair of aluminium aftermarket valves for my bike, I live in Argentina so original valves are hard to find. They are very well built and fit perfectly on the bike. The problem is that they don't have any markings at all, no punch marks for timing and no groove for right side valve. I could figure out which valve goes where, but I don't know how to time them with out the punch marks. Could any one tell me on which toothe of the gear the punch mark goes using the lowest point of the opening as a reference? or tell me some other way of timing the valves without using the punch marks.
Here is a picture of the old valve that the bike had and the new aluminium ones I found.
