okay, so you made me google!
any one of these would work...
"Even if we were under full scale attack I couldn't move any faster, not and maintain a safety factor." -- Scotty, The Naked Time, stardate 1704.2, Episode 7
"A can't change the laws of physics. A've got to have thirty minutes." -- Scotty, The Naked Time, stardate 1704.3, Episode 7
"I'd love to tear this baby apart." -- Scotty, Space Seed, stardate 3141.9, Episode 24
"The warp drive is a hopeless pile of junk." -- Scotty, The Doomsday Machine, stardate 4202.9, Episode 35
"The shape the thing's in it's hard to keep it from blowin'." -- Scotty, The Doomsday Machine, stardate 4202.9, Episode 35
"I've giv'n her all she's got captain, an' I canna give her no more." -- Scotty, (Several Times)
"She won't take much more of this." -- Scotty, (Several Times)
"This jurry-rigging won't last for long..." -- Scotty, (Several Times)
"Ma barins...ma poor barins." -- Scotty, (Several Times)