I have a 2001 Mercury 75HP 2-stroke outboard which developed an annoying intermittent squeaking noise at around 100 hours. See Youtube clip http://www.youtube.com/watch?v=Vmh8-YReYRA
There is no loss of power associated with the noise and it seems to come and go at random.
I am told that this was a relatively common problem with Mercs in NZ around that date and has usually been fixed by replacing the bottom engine bearing, which upon removal shows no obvious signs of damage.
I had the bottom engine bearing replaced but unfortunately the noise problem persists and is now happening more often. It used to start after several miles fast running but now happens within a few minutes.
A stethoscope check indicates that all engine bearings and gearbox are OK but oil pump area is quite noisy. The squeak is audible outside the motor below the base of the cowling, but can’t be heard through the stethoscope. Removing the cowling makes no difference to the squeaking noise.
Does anyone have any knowledge of this problem and how it can be fixed?
There is no loss of power associated with the noise and it seems to come and go at random.
I am told that this was a relatively common problem with Mercs in NZ around that date and has usually been fixed by replacing the bottom engine bearing, which upon removal shows no obvious signs of damage.
I had the bottom engine bearing replaced but unfortunately the noise problem persists and is now happening more often. It used to start after several miles fast running but now happens within a few minutes.
A stethoscope check indicates that all engine bearings and gearbox are OK but oil pump area is quite noisy. The squeak is audible outside the motor below the base of the cowling, but can’t be heard through the stethoscope. Removing the cowling makes no difference to the squeaking noise.
Does anyone have any knowledge of this problem and how it can be fixed?
