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2011 bf50 Honda

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Walleye hunter

New member
Good day everyone,

I have a 2011 Honda bf 50 tiller. The motor has relatively low hours 350 range plus or minus 50. History of the engine. At approximately 5-10 hours the motor hit a rock snapping the drive shaft. A new gear case was installed by insurance. I purchased the motor from a buddy about 6 years ago. Since I’ve owned it, it has always made a squeal on deceleration and deceleration only. He said it’s always made that noise. But I know an outboard shouldn’t. I do not have a rpm gauge. But it occurs on deceleration 17-14 mph. The slower you decelerate the less you hear it. I have a video of it making the noise. But I can’t seem to upload do to file size. Any ideas?
 
Hi,

I've never worked on a 50hp so....
...there's that :)

My question to your buddy is; did it squeal like this BEFORE or AFTER the rock strike? Hopefully you already know the answer or can still ask him about it.

Does it do this when in gear only or in neutral too?

If it started doing this AFTER then it's probably related to that. That's not necessarily a certainty but it's something to consider.

The sound only occurring as the engine rpm slows OR as boat speed drops says changing THRUST to me.

If the noise happens in gear only, I would first suspect and inspect the propeller thrust washer. It's a high wear item and is often affected by debris in the water like fishing line and rope strands. The washer should be smooth on both sides. Any sign of ridges, pits or gouges means replacement is necessary. It's actually best to compare a new one to the old one if you're not sure but keep in mind I think those can get put in backwards.
See item 17 in link directly below;


If it squeals both in gear and in neutral and started doing that AFTER the mainshaft and extension case were replaced it might mean that the accident could have damaged one or both of the crankcase thrust washers. It will be difficult to prove that without a major engine tear down but the crankshaft thrust can be measured with the engine still assembled.
See items 10 in link directly below:




If it squeals in neutral and did so BEFORE the rock strike, I might suspect that the overrunning clutch inside the starter motor could be making the noise. That is, IF it has a starter.
See item 3 in link below


If it's pull start only then you might want to focus there as pull start assemblies do make noises sometimes.

Of course I could be all wet with my ideas and that sound could be originating other places on your outboard. For that, I offer the following:

You can make a "poor man's" stethoscope by cutting the bottom out of a windshield wiper fluid bottle and pushing a length of automotive heater hose into the spout.
It makes an effective listening device that won't injure you or damage anything if it gets accidentally knocked out of your hand. IT FLOATS!...I think:unsure:

Using the thicker washer fluid bottle to make one rather than a thin oil or antifreeze bottle works best for transferring sound. Works GREAT for narrowing down where mechanical noise is coming from.

Just some ideas on the subject.

Good luck.
 
I had asked in the past and he had said it’s always made that noise. Now before the impact I’m not sure. And he probably wouldn’t remember either. I was reading it could be the prop itself and the style of 4 blade (solas). I have the wrong pitch but a spare, also a solas so I’m gonna start with that in a few days and see what happens. I did find some posts regarding the solas prop itself being noisy. But will definitely check out the thrust washer. I didn’t realize that it was a wear item itself. If you rev the motor up slightly not necessarily to 17mph but out of gear no noise so it has to be something in the drive line. Is there any bearings in the midsection? Did I miss lubricating something while doing the water pump, although before and after pump same noise.

No noise in neutral, no noise on acceleration or while running at mid range or wide open. Only deceleration for that brief couple of seconds while it’s winding down
 
Well, starting with the prop sounds logical to me and will give you a chance to check out the propshaft thrust washer. Those protect the gearcase and are often neglected/ignored. I always keep a spare new one on board in the tool kit. Too bad your spare.prop isn't a 3 blade stock one.

Also, pulling the prop periodically and checking for line wrap on the shaft can save you a bundle of cash and prevent heartache. I call monofilament fishing line THE #1 CAUSE of propshaft seal failure.

I did look for a midshaft bushing for the 50hp but didn't see any listed.

Something that comes to mind, although probably completely unrelated, is the older, carbureted Honda 50 sound muffler making a "knocking" or piston slap type noise due to it's design for increased air flow.

I haven't heard or read anything about the EFI 50 induction system making unusual noises but I suppose anything is possible.

Good luck.
 
I put the spare prop on, 12 pitch 3 blade solas vs the 4 blade 14 pitch solas that was on it. No longer makes the noise on deceleration at 17-14 mph. The same noise comes present on acceleration at about 3 mph for a sec on take off. So I believe the issue is in the props. I had read solas/honda props can be noisey. I have a 14 pitch 3 blade Yamaha just to verify the noise disappears all together and then will replace with a merc spitfire 4 blade I think
 
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