Honda 50hp noise

[tjcooper]

 

[tjcooper]

It does not make noise when lower unit is off,
Do would think tensioner is ok, belt ok.

Drive shaft, it may be part of the standard operation, but I believe something is off, maybe bearing under flywheel?

 

[jgmo]

If it's an X extension case, it could be the midshaft bearing. Does the .mainshaft show any signs of undue contact? That's what it sounds like to me but just a guess.

See items 10 and 13 in the link.

https://www.boats.net/catalog/honda/outboard/2007-and-later/50hp/bf50dk2-xrta-vin-bbej-1100001-to-bbej-1199999/extension-case

Good luck.

 

[tjcooper]

Thx for reply, is a 20 inch, so I don't see a midway bushing. I see hole in case, then a view of the receiver of the splines. Shaft looks ok so do splines. Maybe this is normal whine? My 20hp never did. I greased up all, splines and shaft, checked water pump put it back together and noise is still present after test run.

The noise is gone with the removal of the lower unit and vertical drive shaft. (I ran engine quickly as no water). Which is weird because the shaft is towards the bottom of crankshaft but noise seems to be at top of crankshaft as seen in video.

Which leads me to believe it is between two parts, the shaft or the receiving end. Or a bearing. Or maybe a freaking straw is I. There....hahaha. one end being the crankshaft and oil pump. Or it is rubbing where I cannot see, but no noticeable wear marks on driveshaft, other than up by the seals towards splines which should be normal.

800 hour motor

These are unknowns to me as I've never been in that part of motorland, just saw videos of how to remove power head on YouTube.

 

[jgmo]

What year?
Model...50D or 50A?
In other words, fuel injection or carburetors?

 

[tjcooper]

2000 50A carbs

 

[tjcooper]

Video attached

 

[jgmo]

Ahh HA!

That noise could be normal!

There's a paragraph in the Honda Marine Carburetion Manual that describes how the 50A engines create noises louder than other engines due to the design of the air induction section of the.....
....wait for it....


..MUFFLER!

They call them mufflers for that reason but the carbed 50 is unique.

I will find that in the book and post it when I can.

 

[tjcooper]

 

[tjcooper]

Not a failing part? It sounds like the gears meshing on the splines.

I just don't get why pulling the lower unit makes noise stop....other than it is the splines making noise and resonating to the top of the crankshaft....but just guessing at this point.

Thanks for your input,funny thing is my video went viral, 1.8k people watched the YouTube video. Must be a slow day for new content or people think it is some ASMR vid...hahaha

 

[iang6766]

You have a delaminating magnet on the flywheel clipping the coil, very common on these

 

[tjcooper]

I'll pull flywheel to check

 

[jgmo]

Well, I think you'll probably find Ian is right....he usually is.

His explanation matches the noise in the video probably better than what I thought it might be.

But here's that paragraph from the carb manual just so you have it anyway..

Good luck.

 

[jgmo]

Grrrrrrr...stupid site wouldn't load the photo.

 

[tjcooper]

I agree with the last sentence entirely. Thank you.

However, the flywheels coming off to take a look see, so much better to do this on land.

 

[jgmo]

Yes, absolutely! I hope that you find some clear evidence that you can
make a decision on.

Please let us know what you find.
With picture if possible.

Thanks.

 

[tjcooper]

Took flywheel off. Looked ok, 2 statorsupon were wrapped in cloth, 1 was plastic case.

Upon closer inspection saw Mark on flywheel stator and on a couple magnets. Buzzed them all down w grinder , reassembled and texted.

Noise still there hard to say if louder or less, I'm hoping it solved, but still noisy IMHO.

I'll try to get video update

 

[iang6766]

The magnet eventually delaminates and destroys the coils too. Only fix is a new or good used flywheel. I've tried all these thinks before. The manet has a very small clearance from the coil, once it starts delaminating it's stuffed.

 

[bobmech]

Not sure about the timing belt, but your timing belt tensioner bearing needs renewal.

 

[tjcooper]

Agreed, prob Original belt.

I had first suspected tensioner making the noise, can see some oxidation on tensioner chrome.

I will prob try again with the lower unit off to compare. But I recalled the noise disappeared after dropping the lower unit.

 

[tjcooper]

Droped lower unit, noise is less, but still there.

Last time I dropped it ran it with no water, this time I shoved hose up water tube w lower off.

Unfortunately, the whine still there so I was wrong about it disappearing, just was a bad test before.

Back to grinding down the magnets and or Coil
I also used endoscope to examine, pretty cool app for a phone

 

[tjcooper]

Removed lower and ran w water tube connected to hose.

Noise still present, so I was incorrect on the noise disappears, it seems I Lil bit less with shaft disconnected though.

Got a endoscope shot, can see the case before female end.

 

[tjcooper]

Running idle

Video w lower unit off

 

[tjcooper]

Whining w rpm lower unit off

Video link

 

[tjcooper]

Well, I am stopping for now.

After grinding off material on magnets andDone w flywheel coils, l used marks a lot black felt pen, testing with lower unit off, the flywheel is not contacting coils or anything else.. I also carefully cleaned flywheel of any material that could interfere with engineered tolerances.

I also shimmed the coil mount holes to attempt pulling coils back from rotating flywheel.

next up spark plugs and possible carb cleaning, belt and tensioner. I changed Upper and lower oil.
Order parts...