Hello all, new member and as you can tell I'm having touble with my cam timing. (1972 Datsun 240z motor) (cam is recut/ground) New chain and gears, lined #1 on cam gear and lined up on crank mark. Ran engine and alot of poping though the carbs, checked timing again and the chain has poped back 2 positions on the cam gear mark. When installing the chain the tensioners were tight to keep all the slack out of the chain. Went back in, retimed and tightened adjusters, now it still pops through the carbs and the timing has jumped back 1 on the cam gear. What am I missing, any help would be appreciated....Lee.