I have a 1992" Mercury 150 XR6, that was recently rebuilt by a reputable marine dealership after it ran out of oil. My question is, it is making a noise during idle, especially when it is tilted to run in a shallow water area. The noise reminds me of a sticking lifter on a old chevy motor. Once I accelerate the noise goes away. My son tells me that I am hearing things. The motor rebuild is still under warranty and I have had it back to the dealer, but they can't find anything wrong with it. If you run it with a motor flush attachment, you can't hear it because the motor exhaust is much louder than the knock. The motor has to be in the water to hear the noise. Is this common?
