Logo
FULL SITE MENU

2015 Mercury outboard four stroke 60 hp noise on deceleration

J

Jtope

New member
Hello,
I recently purchased a 1650 rebel xl lund with a Mercury 60 hp four stroke. I have been concerned with this loud ratcheting noise when decelerating. Mercury has told me that this is normal as well as the tech where I bought it. I have never heard a noise like this on my older engines before. Has anyone experienced this? If so can someone explain the reasoning behind this? This song DNS like metal on metal and I am worried about wear or it breaking. Any information would be great.
Thanks!
Jim
 
They are correct.---------Slow down gradually and there is no problem.---------------Do this , in your driveway put the motor in forward and try and turn your propeller by hand.------It may help you understand.
 
racerone said:
They are correct.---------Slow down gradually and there is no problem.---------------Do this , in your driveway put the motor in forward and try and turn your propeller by hand.------It may help you understand.
Click to expand...
Thank you for the reply. Will this wear the gearing system out any faster than normal?
 
Most noticeable on those "two speed" outboards - the ones that are either in neutral or full throttle with nothing in between.

Easing the throttle both up and down when accelerating and decelerating stops the noise and saves a bit of gas and reduces the stress cycles on the transom.

The noise is caused when the ears on the gear is slipping (ratcheting) over the clutch dog that is driving the prop shaft.

So while it is a normal function of the way it's built, anytime metal corners are slipping against each other, even when immersed in the gear oil, their is libel to be some minute wear (or minimally stress on the edges) which over time will take a toll.

If you don't put your car into gear and then ram the gas pedal to the floor and then stop by putting the brakes on causing a four wheel lock-up every time you brake, why treat your boat motor that way - ease the speed up/down - your motor will last longer.
 
Last edited:
Pretty much all of the Merc's will - it's simply the design of how the gears interact with the clutch dog - it's partly a safety thing as well. If the prop gets stopped dead, while in "forward" gear (hits a rock, or bottom etc), it will allow the prop to "stay stopped" and the dog slips against the gears so they don't get chewed up.

When you decelerate uber-quickly you are in effect "stopping the prop", due to the water resistance, and the clutch dog "slips" resulting in the ratcheting noise as the rpms of the motor (slow) at rate "slower" than the turning of the prop (so the motor is still running faster (in rpms) than the prop is (allowing for the gear ratio).

Doesn't make it a "good thing" but better than chewing gears. Having to replace a clutch dog on a Merc (or any brand that uses the same technology) is not exactly an unheard of occurrence. Ratcheting, over time, rounds the ears off the dog and causes slipping due to an improper (mesh) with the gears.

"Granny Shifting" can have the same effect (the grinding sound you get if you shift in/out of gear slowly does a number on the ears of the clutch dog). So while it's prudent to "quickly shift" in and out of gear, once in gear it is "prudent" to ease the throttle either up or back.
 
Last edited:
????--------When you decelerate quickly the gears slow down but the prop keeps spinning due to the forward motion of the boat !!!!
 
racerone said:
????--------When you decelerate quickly the gears slow down but the prop keeps spinning due to the forward motion of the boat !!!!
Click to expand...
That's the correct explanation. Do other hp models do the same thing?-- yup. Will it wear the clutch components-- yup, in about 10-15 years. The reason you are able to hear this more on newer outboards is because newer outboards are just sooo much quieter.
 
i am running a fairly new (2011) merc 60 hp 4stroke...the only time you should hear that is when you have an emergency and have to jerk the throttle back all the way in an emergency....if you are hearing it often i would suspect you are dogging the motor..every motorized vehicle,car or boat or truck or lawnmower etc,has its own feel..you know when you are pushing it to the limit and beyond...go beyond and on an outboard and you are looking at expensive repairs and reduced lifetime..

thats the reason i dont loan my equipment...especially my boat or my truck....
 
Back
Top