i have a 04 yz250f, i'm a car mechanic and see nissan maximas with over 200 links in the timing chain, and 19 more valves than my bike go over 300k miles. ford mustangs and pickups with dohc and 27 more valves and valve springs and just as many links in the chain go over 250k miles, all with original hydraulic tentioners and guides. why do we have to do timing chains so frequently? Also i would like to know what the pros and cons of the hotcams would be for my bike?(besides shortened timing chain and valvetrain life) or what the best overall mods are for power and handling. best exhaust? high comp piston?chassis/unsprung weight loss? Can anyone please tell me which type of forks are on my bike. its stock. id like to service them myself, but dont know if its cartridge or dual chamber or...? thanks in advance, all input welcome!