# Mercury 60/40 4 stroke



## 1darknight

I have a 2012 new Mercury 60/40 Jet 4 stroke. At idle, maybe 600 to 800 and up to a 1000 rpm the jet pump resonates/vibrates/ or rattles and is noisy, above 1000 rpm everything is just fine. My previous Yamaha jets never were noisy at idle. Is this normal or something to be concerned about, it occurs both if engine is on the water hose or in the lake. Thanks.
Bill from Alabama now.


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## semojetman

I don't know for sure.I have a 2013 60/40 4 Stroke and doesn't make any noises at any RPM


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## smackdaddy53

Is the bearing going out, have you lubed and flushed it after every trip?


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## jackpen

The motor will rattle at idle and shut down when the impellor nut is loose. The impellor will ride up on the shaft and be quiet under load. Check the nut and make certain it's tight.


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## 1darknight

Thanks guys, Its a new 2012 engine, maybe 2 hours on it. Yes I have greased the jet with the proper grease gun and lubriplate grease #630AA . Taking the Mercury 60/40 jet to Bass Pro Montgomery Al Thursday to see what they say, it is under warranty and hopefully they will fix it. Maybe the impeller is a little loose and under-torqued. Or maybe a bad bearing it is. I will post the outcome after bass pro c/o . All my previous four Yamaha jets were trouble free., and had several years use on them.
Thanks,
Bill


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## jbnelson

I agree, tighten up the nut and that should fix it. I had the same thing happen with my jet (different motor than yours).


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## 1darknight

Bass Pro Montgomery AL checked the Mercury 60/40 4-Stroke out they said. But nothing accomplished. They did not even tighten the impeller nut, all they did was raise the idle speed from 750 rpm to about 950 rpm and kept it 7 days. Before I travel all the way to Missouri to Troutt & Sons. I need to try and tighten that impeller nut myself some how. How do you hold the impeller while tightening the nut,? A block of wood maybe or is there a proper way? They did verify that the engine had 3 hours on it.
Thanks from  Bill


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## Genius

My new 60/40 picked up a rattle within a 1/2 hr of run time, so I need to check it also ...if I only new how?


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## 1darknight

Well I got bass pro to return the idle to 750 rpm's today. Then I called Troutt and Sons in St J  ames MO. They carefully explained to me that Mercury uses a stainless impeller and what I hear at idle 750 to 950 rpm is a harmonic rattle and actually the impeller is rubbing the liner during that time a little causing the resonation sound.. They said with only 3 hours on the motor just run it and by 10 hours or more it will quiet up some and to just get the rattle out of my head and do not let it haunt me. He said no need to bring it to him as its a 600 mile trip. He said even a brand new Merc 60/40 will do it at idle. So I appreciate his explination and can or will live with it. My previous Yamaha's were very quiet but they all had aluminum impellers. So case closed for me for now.
Thanks for your inputs and Troutt and Sons knows their stuff.
Bill


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## smackdaddy53

That still does not sound right, if it rubs the liner at idle wont it wobble more at higher rpm? Hope mine does not rattle


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## Genius

So.. me and a friend who also just bought a 60/40 took both our boats out for the 1st time together.
As I mentioned mine started to make a noise right off idle, not really at idle....
It kinda sounds like a squeaky belt and somewhat of a bad bearing, like maybe a bad alternator on a car.
His seems to be fine. I did tilt my engine up today and had a look with a flashlight at the impeller, it looks fine,
no scuff marks that I can see.
I guess I'll pop the cover off over the belt this weekend and have a close look at the pulleys.
My next idea is to put it back in the water and take my stethoscope with me to pin point the noise.
1darknight, dose your noise sound like what I described?


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## smackdaddy53

That sounds like a bearing going bad. Squeeze grease in the fitting and if it does not come out the other end (the hole or tube next to it) you are not getting lube through the grease ports to the bearing. A bearing running dry screeches and will not cause the impeller to fall and contact the liner until it begins to fail nearly to the point that the balls are gone and the bearing falls apart. 
Mine was the same way when I bought it and the grease ports were salted up so bad there was no way for grease to get to the bearing...


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## fishbum

1darknight said:


> Well I got bass pro to return the idle to 750 rpm's today. Then I called Troutt and Sons in St J  ames MO. They carefully explained to me that Mercury uses a stainless impeller and what I hear at idle 750 to 950 rpm is a harmonic rattle and actually the impeller is rubbing the liner during that time a little causing the resonation sound.. They said with only 3 hours on the motor just run it and by 10 hours or more it will quiet up some and to just get the rattle out of my head and do not let it haunt me. He said no need to bring it to him as its a 600 mile trip. He said even a brand new Merc 60/40 will do it at idle. So I appreciate his explination and can or will live with it. My previous Yamaha's were very quiet but they all had aluminum impellers. So case closed for me for now.
> Thanks for your inputs and Troutt and Sons knows their stuff.
> Bill


 They are correct! the liner/impeller are almost never centered togeather. the water pressure will center it with higher RPM. You can Play with the liner some to see if it will change the sound, remove the intake, look at the gap between liner and impeller, if it seams offset spin the linner a hole or two ck again, this can make a difference. also some people will open the holes in the liner a bit so they can get the gap even, some people tighten the gap to the liner as well to get more performance but will make that sound at idle more. Enjoy!


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## Lil' Blue Rude

I'm calling BS on Troutt and Sons. I've never seen or heard a stainless impeller do something like that. Both my motors have them and I know of alot of people that have stainless impellers in there's and they don't make any extra noise.
I have had a impeller nut come loose on a 60/40 2 stroke merc and it had a high pitch wine to it at idle. Liner and impeller both had gouges in them.
Not sure what's causeing it but somethings not right with your motor.


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## semojetman

sorry, i dint realize you had a stainless impeller.
my '13 merc has an aluminum impeller.
so it wouldnt really compare


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## Gulf flats Ken

I have a 2019 Merc 60 40 jet and it’s done this from day one at idle. It is the impeller rubbing the wear ring.

I don’t want to have to get over the noise on a new set up with 14 hours.

You can see wear on the ring the lower left 1/3 the rest looks new. I’m taking it back and expecting them to fix it.

This should not happen period especially on a factory set up. Very unhappy with it.


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