Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 137Get this manual
IMPORTANT: Pi ston must be correctly Installed and positioned as ollows: Pistons with the leiterP" must be instal led in he port side engine and the letterP" facin up toward top of eng inePistons with the letter "S" must be insta ll ed in he starboard side engine and the letter "S" facing toward top of engineTOP
34T hread con necting rod screws finger-light while check ing for correct alignment the rod cap35Tighten sc rews (using 38"12 point socket) evenly in three prog ressive steps until torquedNOTE: Torque each rod bolt in equal increments, concurrently, to 360 lbin (40.7 Nm) Then rotate each rod bolt an extra 90 (14) turn
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