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BF225 2006 Trouble Knocking

maxthrottle

Contributing Member
My port engine just developed a knock at low and high revs but only in neutral. Putting the engine in gear either forwrd or reverse and the noise goes away and it behaves normally. The sound may be like the racket the engine makes just before it engages into forward or reverse? Engine has about 550 hours. No alarms or codes or lack of power. The lower unit and prop look fine. Gear oil has about 150 hours on it though. it's in the water, kinda of a pain to pull it without a trailer. Any idea on what this could be???
Thanks,
Bob
 
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Thanks for the replay Kstafford. Mid shaft bushings could be problem . Do they make noise in neutral and then disappear under load? The water pumps were replaced 4 years ago, at that time the mechanic said they were OK. Engines are 25" shafts with 550 hours I'm told this happens more often on the 30's? I was hoping this would be a shift cable adjustment before pulling it. Where is the x ray vision?
 
Both of my motors are 2008 bf 200s 25" shafts @ 340hrs i did both of them and yes they sound like a power head issue for sure in neutral. They don't make much noise when loaded because they are leaning into the bushing under load. I was lucky enough to have the newer revised style midsection which has a redesigned bushing support. When you start reading up on the horror stories it can be scary. I got my boat in march of this year and when i ran them in the barrel it really freaked me out how loud it was and it knocks hard all through the crankshaft. I replaced both bushings and lucky my shafts were not badly gulled. If this is your problem it is certainly better than the alternatives.
 
Wow, you describe the same engine symptoms that I am having. my engines are 2006, i have no idea what bearing support was used I'll call the marina this week and see if they can pull the boat and get this done before a hole is blown thru the side. I have Progressive propulsion plus insurance to cover any trouble with the lower units, maybe Flo will help me out with this repair. I'm hesitant to go offshore again without fixing this trouble. One engine does not get my boat on plan max speed about 10 MPH.
I had no idea this was a common problem, thank you for your response. Bob
 
Yes indeed it is a Routine maintenance item that Honda should have probably suggested replacing every 200 hrs or so cheap enough to buy and pretty easy to replace. Drive shafts and mid sections not so much....
 
Also if you use a piece of pipe or a wooden dowel and put your ear on one end and the other up and down the midsection you can really narrow down the noise. like a poor mans stethoscope. good luck.
 
Honda Mid-shaft bearing

Very Good video on the procedure: https://www.youtube.com/watch?v=44ZaDzNck1I

Part Numbers
• Bushing = 40210-ZY3-610 – (Vertical shaft bearing)
• C ring = 9052-ZY3-000
• Flat washer = 9053-ZY3-610
• You’ll also need a pair of snap ring pliers.

Removal
Put engine in forward gear.
Remove the lower unit as if you are going to change the impeller on the water pump. Don’t forget the bolt under the trim tab.
Look up inside where you pulled out the drive shaft. There you will see the bushing held in place by a C clip, riding on a metal flat washer. Remove the C clip. Pull out the bushing.

The outside of the bushing is rubber with a metal bushing inside. That metal bushing rides on a raised section of the drive shaft.
To get the bushing out use a pilot bearing puller - Autozone part 27128 loaner tool
Clean out any corrosion and grease the bushing inside and outside liberally with marine grease. A two inch wide wire brush on a drill extension works well.

Installation
The cut-outs in the bushing go up toward the motor.
 
Thank you everyone for the help with this. The engine knock is quite noticable in neutral and getting worse. This is too big of a job for me to take on by myself so I'm going to try and get an appointment at the Honda dealer to have this taken care of. Should I be concerned about the driveshaft?
 
Sounds to me like cable adjustments, not going into neutral properly, I have never heard any kind of noise caused by the support bush and I have seen some bad ones. Disconnect the shift cable to allow the shift lever to fall into neutral then run the motor and see if the noise goes away
 
The knock was a bad lower unit bearing and gears on the port engine. Two teeth are crunched. Needs a completely new lower unit. The starboard engine has a golf ball sized hole where the mid support bearing used to be. Fingers crossed Flo at Progressive and the propulsion plus will help with the repair $$$. The power head ECU's were scanned, everything up top is tip top. I had no idea of the chaos going on below the water line, looking forward to smooth and robust BF225's again soon.
 
OUCH! Hope the insurance comes through. About the golf-ball hole in the mid-level cowling. Try to get a replacement made in 2008 or later. It is my understanding that those were re-engineered to have much more water flowing over that mid-shaft bushing to keep it from failing.
 
The marina wrapped up the repair yesterday. Brand new lower unit on port side and a new mid section case and bushing on the starboard side. Progressive Propulsion Plus paid for everything except the mid section case. No idea why the lower unit gears and bearings were damaged. The propulsion plus insurance rider was the best $139 I spent, the insurance company was fast and generous.
 
And you are a lucky dog! LOL! That is great to hear. Happy boating.

Would you mind posting the source and the cost for the mid-section case? I think others would like to know.
 
Yes, I got lucky with the insurance coverage.... this time. The case kit on the repair invoice is #04406-ZY3-611ZA Part price was $583.75. Labor to install was 3.18 hours. Just about $1K all together. Mid shaft bearing failure = B.O.A.T.
 
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