Motorcycle Engine Cover Seal GL1800A GL1800B NRX1800 Fit For GL1800 Goldwing 1800 2001-2017 GL1800A GL1800B GL1800C NRX1800 04-05; sealing gasket for motorcycle left cylinder head matching engine mating surface die cut OEM shape with aligned bolt fluid channel holes; fits mounting position directly without or grinding multi layer sealing surface blocks oil coolant penetration; retains stable tightness under long time temperature operation composite blank base; integrated flat pressing craft; uniform smooth texture over full gasket plane OEM matched overall dimension consistent thickness; evenly distributes bolt clamping force to reduce warping risk