2004 mercury efi 50hp 4 stroke problem

[brasser]

Hi there fellow boaters. I was wondering if anyone has had the same problem that I've got at present.My 50 efi 4 stroke has a real growl coming from gearbox only when in neutral.Have had gearbox inspected with bearings replaced,told everything else is brand new, as it should be after only 117hrs. Servicing mob do not know what noise is.
Regards
Brasser

[Roughasguts]

Does it growl when you spin the prop in neatral with out the motor running??

[SNAPPERCOFFIN]

Does it growl when you spin the prop in neatral with out the motor running??

You would hope the servicing mob would pick up something as simple as an adjustment of the gear lever.

[Steeler]

Hi

Yeh i was also thinking along the same lines as snappercoffin,the selector not properely located,but that i would think is a gimmy for a service centre.

Cheers

Steve

[Mike Delisser]

Hi

Yeh i was also thinking along the same lines as snappercoffin,the selector not properely located,but that i would think is a gimmy for a service centre.

Cheers

Steve
Hard to understand what you mean by growl but my 60 efi 4st merc had something you might call a growl in neutral. Only heard it when out of the water (flushing). All fixed after I adjusted the gear selector.
Cheers

[brasser]

Does it growl when you spin the prop in neatral with out the motor running??
Hi Mate
No it doesn't,the bloody thing only makes this noise when I knock it into neutral.
It isn't gear lever adjustment either,which has been checked by service centre.
This noise is probably louder than when the motor is doing 2000rpm
I have been told that this might be a manufacturing sound, but most 4 strokes that I have heard are pretty bloody quiet, when running and especially when at idle
Thanks for your interest

[Roughasguts]

Then, there must be some pretty loose tolerances in the gearbox causing the noise. Must be bad shimming or wrong spacers or something causing the noise.

Next time with the motor running! hold the prop in neatral or turn it, see if theres any vibration or grating.

What oil has gone in the gearbox it's not thin stuff is it.

[brasser]

[quote=Roughasguts;986291]Then, there must be some pretty loose tolerances in the gearbox causing the noise. Must be bad shimming or wrong spacers or something causing the noise.

Done the prop stuff, correct oil in gearbox, it's a real mystery. I think my best bet is to listen to the same motor at some stage.
By the way, noise is present both in and out of the water, with the same volume.
I will keep you all informed of progress,if any.
Thanks to everyone.

[Roughasguts]

Theres only one other thing I can think of and that ain't gearbox related.
And that's the timing belt hitting a cover or badly aligned or badly tensioned.
(so the belt is slackest in neatral) Sorry clutching at straws but still possible.

When she's running get a long handled screw driver and place the tip on the gear box and the other end in your ear! use as a stethescope and move up from the gearbox to up near the top until you find the distinct noise at it's loadest.

[Mike Delisser]

If the noise is the same both in and out of the water it won't be the gear box.
After the first service of my 4st merc my mechanic mentioned that I may hear a suction sound (????) from the motor while idling in neutral and not to worry about it.
Cheers

[frankgrimes]

Done the prop stuff, correct oil in gearbox, it's a real mystery. I think my best bet is to listen to the same motor at some stage.
By the way, noise is present both in and out of the water, with the same volume.
I will keep you all informed of progress,if any.
Thanks to everyone.

Hey mate - Got same motor....more than welcome to listen to mine....I'm on the Goldie though.

Mick

[brasser]

Thanks for the offer, bit far, I'm in Sydney
Maybe someone in Hills District has same motor that wouldn;t mind me having a listen
Thanks Mick

[TheRealAndy]

We have a newish one at the yacht club as a rescue boat. I think it was bought 2 seasons ago, so about 2007.

I was sitting out in it the other day after laying a course and I noticed it was making an aweful noise at idle too. I couldn't pin point the noise but i dont think it was the gearbox. This motor has less than 50 hours on it from memory.

I have a 50hp yammie not efi, compared to the merc its heaps quieter. The merc is definately a lot louder at idle, and the TTpump is a lot louder too. Looking at the two engines with cowlings off one could be mistaken into thinking that merc is actually a yammie. Even share the same fuel fittings.

[dean grieve]

Hi there fellow boaters. I was wondering if anyone has had the same problem that I've got at present.My 50 efi 4 stroke has a real growl coming from gearbox only when in neutral.Have had gearbox inspected with bearings replaced,told everything else is brand new, as it should be after only 117hrs. Servicing mob do not know what noise is.
Regards
Brasser
if is the gear box that i think it maybe just above your waterpump the shaft is wider for a bearing grease the shaft mostly takes the noise away others have this growl that for unknown reason

[foxx510]

Looking at the two engines with cowlings off one could be mistaken into thinking that merc is actually a yammie. Even share the same fuel fittings.

I thought they were actually Yammy powerheads in the Merc 4 st engines.

[Tim_N]

They are Foxx510.
Tim

[black runner]

I have read on other forums of similar merc noises (when I was tracking down what eventually ended up being an exhuast noise on my Yammiea). There appears to be three main causes:

Shift lever adjustment to ensure no partial engagement of the dog clutch in neutral.

Insufficient lubrication of the driveshaft bushing in the upper case.

Instances where the driveshaft rubs on the exhaust adapter plate when in a no load condition? (sounds a bit sus I know)

Cheers

[Spaniard_King]

Insufficient lubrication of the driveshaft bushing in the upper case.

Cheers

This is the most common fault for suspicious geabox noises. Drop box grease bush reinstall box.. problem will go away for a few 100 hs;)

[aussiebasser]

Next time with the motor running! hold the prop in neatral or turn it, see if theres any vibration or grating.




Whilst being very very careful!!! Do not hold the prop blades while doing this!!! If it is a selector issue, and the keyboard mechanics don't really know, you could very easily inflict injury on yourself by wobbling the prop with the motor running.

[dogsbody]

If it's a growling noise I think it may be a bit of extra grunt trying to unleash, It's a MERC after all. 8-)

Dave