pretty sure your tc has an auto decomp device on the exhaust cam as has been mentioned, and I think it should be looked at .what wears is the nub on the bottom.i think xriderdown is on to something here.dan
I have the manual that came with the bike, it refers to the TC, TE, and TXC. It clearly states in the manual that the TE and TXC have both auto Decomp and manual. The 2008 TC 510 only has a manual decomp. The manual has seperate instructions on how to start the TC with manual decomp and TE/TXC with auto decomp and manual decomp. At the dealership in Mitchel Ontario Canada that sold me the bike new, the owner Scott Rocher took me aside and explained that the bike only has manual decomp and he showed me the steps to start the bike. It has been very reliable and easy starting until now.