Need some help with my outboard...

[Jason]

Hoping to get some thoughts from others on a problem I have with my outboard.

Some background:

It's a 60HP 4 Stroke Yamaha outboard made in 2003. I was in the Pine River about 12 months ago doing some fishing with my young bloke when I ran aground on a rocky/shale bottom, not large solid rocks, probably about half a fist size. I had to replace my prop afterwards and it also started making a pretty bad whine around 1500RPM, the noise stops at about 2000RPM. There is no noticable vibration, just the whine.

Here's a vid of the noise:

[YT]https://www.youtube.com/watch?v=RoJJnmypY5k[/YT]

Since the noise has started it has had a full service and also had the lower unit removed to check the clearance of the drive shaft, the noise is still there.

I'm pretty convinced now that the problem is in the gearbox, it dosn't make the noise when the boat is out of the water, it needs the pressure from the water to make it occur. Perhaps it's a thrust bearing? It also doesn't make the noise around 1500 to 200RPM in reverse, only forward. More ammo for gearbox/thrust bearing fault.

What do you guys think? Anyone with any outboard knowledge/skills?

Has anyone stripped an outboard gearbox before? I'm happy to give it a go as long as there are no pitfalls?

Cheers for any help.

Edit: The new prop is fine, it clears well and there are no telltale rub marks where it might be touching. The motor hits 6000RPM so it appears to be well matched.

 

[d22dave]

I know you say the new prop is fine, but any chance you could borrow a prop and just give it a try

 

[Jason]

Yeah I probably could, perhaps even just buy a Yammy one and keep it as a spare.

The new prop is a Solas, it is black powder coated aluminium so it would be easy to see if it was rubbing anywhere.

 

[Matt76]

What a bugger mate, I haven't heard a noise like that before but as you say sounds like a bearing or shaft rubbing. Are you a member of ausfish.com.au? There are some pretty cluey blokes on there (and a lot of wankers as well).

 

[d22dave]

Yeah I probably could, perhaps even just buy a Yammy one and keep it as a spare.

The new prop is a Solas, it is black powder coated aluminium so it would be easy to see if it was rubbing anywhere.

I was thinking more a balance thing, although you did say no vibration

 

[Jason]

What a bugger mate, I haven't heard a noise like that before but as you say sounds like a bearing or shaft rubbing. Are you a member of ausfish.com.au? There are some pretty cluey blokes on there (and a lot of wankers as well).

Hey Matt, nah not a member of Ausfish, I'm on the old BFO so I might ask on there.

 

[Jason]

I was thinking more a balance thing, although you did say no vibration

At full noise it goes really well, no whine at all, just the 1500 to 2000 RPM range.

 

[Matt76]

Nice bait board by the way lol

 

[Jason]

Ha ha, yeah it's a friggin ripper! Back on the tools on Monday hey?

 

[Matt76]

Yeah mate. Doing heavier mild steel stuff and ally, I'm looking forward to learning some new stuff. They've got their own powder coating booth too!

 

[Old.Tony]

It sounds like metal-on-metal in my headphones, but I'd wonder if it's happening as a harmonic - maybe a very slight vibration that's present from a minor bend in the lower shaft. I wonder if a sleeve bearing is turning in its mount (so the shaft is turning inside the bearing, but at those RPM the shaft "grabs" the bearing and spins the bearing)?

 

[Jason]

Thanks Tony, pretty sure it's not a harmonic.

It could be a sleeve bearing/bush turning in a housing, I'm not really sure of the components inside the lower unit/gearbox.

I haven't had any luck finding a service manual online for it either. It's a Yamaha F60AET.

 

[Jason]

Oh, and definately agree with the metal on metal observation.

 

[Matt76]

I may not be much help but I'm happy to pass the cold beers if you want a hand to pull it apart.

 

[Jason]

That may be my only option! I'm thinking of having a go at taking apart myself.

Another set of eyes when the springs fly around the shed may come in handy!

Did you end up doing that outboard maintenance course at TAFE?

 

[Matt76]

Nah it got cancelled. I have got to pull the leg off my little 8hp 2 stroke to change the impeller at some stage so am happy to practice on that one if you prefer, it's probably a bit simpler to learn on.

 

[Jason]

I've watched a couple of vids on youtube of oil and impellor changes, looks pretty easy.

Just not sure what I'm in for if I open the gearbox. I don't mind practising on mine either ha ha.

 

[Matt76]

Yeah can't be too hard surely. At least you might see some wear marks or something and know what it is. Someone on BFO might know what it is and save you some guesswork in the meantime anyway.

 

[Jason]

Yeah I think I'll plan to take it apart one day next weekend, hopefully someone can throw some info or possible causes my way in the meantime.

If you feel like coming over for a couple of beers and outboard destruction let me know. I'll try and get some gearbox oil before then as well.

 

[Matt76]

Yep no worries