or anyone else with motor building experience. I got my 2001 xr650r motor in this week and pulled the head and cylinder off to do some inspecting i think that the head may be ported. I have never looked into a stock 650r head, but i would assume it is smooth like other factory intakes. My intake has swirl and i guess what you would call gouge marks like when you have port work done. First question is can anyone measure their intake on their head and tell me what size it is so i can compare it to mine?? Also since the head seems to already be ported i am going to go ahead and put bigger valves in it. Now my question is can anyone tell me what i should go with as far as valves, springs and retainers?? I was thinking about going with the black coated stainless from XR's Only since they are cheaper then titanium, but as far as the springs go im not sure which to get?? I always assumed that titanium was better for performance, but also titanium is very brittle so i thought that they might crack sooner. Is there any truth to my assumption or am i way off here?? Also do the valves just seat against the aluminum cylinder head, or are there steel seats that are pressed in?? I would assume you would want a seat other then aluminum but i cannot find anything on valve seats for the xr650r I would just like to hear from you guys what is better for reliability, steel or titanium and what the reasons are. I plan on ordering all my parts from XR's only so i would just like to hear what you guys would recommend. Also if there is someplace better or cheaper to order these kinds of parts from then please let me know so i can check them out also, thanks.