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2004 BF200 mid-shaft bushing really needed?

J

Jayshow

New member
Hello everyone! I've been using this forum as a great resource since I bought my boat this spring for the wealth of info on Hondas and I want to start by saying thanks to everyone for the insight and info. Until now I hadn't needed to ask any questions but now I have one.
After removing the lower unit today I found the dreaded bushing failure and broken housing issue that I've read so much about.
There is a hole about 1 1/2" wide in the front of the housing inside the outer cover. :( The bushing is gone.
It has obviously been this way for awhile. I've probably put between 30 and 40 hrs on the motor since I bought it and haven't noticed any issues with the lower unit. No shimmy, shakes or noises whatsoever.

My question is how vital is this bushing really? It seems like it doesn't really do much on my shorter 25" shaft since it sits about 4 or 5" above the water pump housing. I can see how it may play more of a role on the longer 30" shafts (like my dads Hondas) but not so much on the 25". Any Honda techs or experienced owners out there that may have some info? Much appreciated and thanks again.
-Jay
 
Are you saying that the failed bushing ate a hole through the out shaft housing? If so, I think you're going to need to get a replacement lower unit.

Opinions seem to vary on the necessity of having that bushing in place, especially on the 25" shafts. In my opinion it should be there. I think that even a very slight wobble in the drive shaft will will cause problems down the road in terms of prematurely worn water pumps, seals, and shaft bearings.
 
I don't know a dang thing about that bearing or why it was specified for that application. I've never even seen one in real life.

Having said that, I can make a few observations based on my mechanical background of 40+ years and a short 6 year career working on Honda's.

I believe the bearing is there because Honda engineering models probably revealed some mainshaft deflection taking place under certain load conditions. Obviously the issue gets more pronounced as the shaft length is increased.

The "certain load conditions" would, most undoubtedly, be "hole shots".

The more the vessel is loaded and the faster torque locking takes place at the prop, the more the shaft will want to "twist" or deflect. If the shaft can't absorb this action quickly enough, it will tend to distort or bend.

Long story short, if you're not out there banging off heavy load, efficient hole shots, you might never notice the lack of that bushing. Even on the XL case.

But with that bushing not there and deep hole shots loading that shaft, catastrophic failure of the shaft is probably much more likely.

Just my opinion.
 
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Had mine fail 2 seasons ago and had it replaced over the winter. I go too far off shore to take any chances. Cost me (in NJ) $1095 for a "case kit" installed by an authorized Honda Dealer.
 
I have replaced mine as a preventative measure. To me I wasn't going to wait til it bored thru the housing...actually I did it when I replaced the exhaust tubes. I would imagine the outboard still functions normal, maybe some noise from the bushing, but most importantly I think if you continue using it like that you could potentially screw up the bearing/seal where shaft meets the engine block, especially with deflection like jgmo mentioned. The take off torque and cavitation torque is what could cause you bigger issue later.
 
Chalk- thanks for taking the time to jump in. Yes the hole is in the front of the extension case where the bushing sits. The bushing appears to have pushed itself out through the front of the case. There is substantial corrosion in the area of the hole an looks to have been this way for awhile. The bushing was totally gone and the hole wasn't noticeable until I took the outer plastic cover off the lower engine mounts.
You mentioned possibly needing a new lower unit... are you talking about the extension case? My lower unit seems fine. Smooth shifting and no noise or vibration. The gear oil is clean, which I had changed to full synthetic when I bought the boat and it's still blue/green.

Jgmo- thanks for chiming in here. I'm not a tech but i've had a good amount of experience working on boats over the years. My dad has made his living as a mobile marine mechanic for the past 40 years so I grew up around boat repair (not that it means much but i've learned a lot from helping my old man) and his thought was similar to yours. He looked at it and said he hadn't seen that happen before but then again he hadn't worked on that many Hondas either. Other makers don't even have a mid-shaft bushing so there's nothing to blow out. If this shaft deflection was really an issue wouldn't all makers have a shaft bushing?

As far as driving/usage of the boat, i don't hammer the throttle on hole shots. I'm pretty easy and smooth on acceleration and deceleration. I'm very tempted to run the engine as it is and just watch it for awhile to see if anything changes.
The boat sat in the water without a lift with the previous owner and the corrosion probably pushed the bushing into the shaft and caused this problem in the first place. Seems to be a poor design unfortunately. Honda is great but even they can have a bad idea.

Anyone know of a 200 or 225 that has run without the bushing for awhile and caused an issue down the line?
My only other thought is the hole in the lower extension case will allow some of the exhaust to escape before it gets to the prop hub... any thoughts on issues this may cause? I can't think of any. Doesn't seem that it would really affect back pressure much.
Thanks everyone!
 
Thanks everyone for your comments.
Quick update.
I'm fixing the issue. Better safe than sorry when you fish offshore like we do.
Fortunately, I recently found a talented local Honda marine tech named Louis who is also a dealer and a wealth of knowledge on outboards and especially Honda. He happens to have a good condition used extension case for $300. He said 30-40 minutes to swap out the case and put in the new bushing. Lower unit is off and side skirts already removed so should be a quick fix. Worth the piece of mind, and when I do sell the boat, I know it's 100%.

On a side note, when I asked him if the bushing was important he said not so much. It was designed to reduce vibration at slower speeds and at higher speeds it wasn't doing much and that my boat was big enough you wouldn't even feel the vibration anyway. (26 CC Twin 200). He also said hole shots weren't an issue with the shaft. I was surprised.
Louis enlightened me that Suzuki's also have mid-shaft bushings.:rolleyes:
If you're in the Stuart/Port St Lucie FL area and you need a good mechanic you should look up Louis Broz.
He worked for Honda for a number of years and has developed improvements that Honda adopted on their motors. The thermostat housing riser was his idea (fixed overheating issue) He is the real deal.
 
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Good for you Jay!
Louis DOES sound like the "real deal. What a great resource to have nearby!

And.......until further notice.......

I stand corrected.

Let us know how she runs after the repairs.
 
The extension case was swapped out on Monday and fresh mid-shaft bushings put in for both motors. Wire wheeled the inside bushing seat area and sprayed with zinc chromate. Once cured the bushings were put in with Mercury 101 grease. Good to go.
Also just finished replacing my battery cables from batterys to engines. Motors were Turning over slowly, like the batteries were bad. Trim motors were working intermittently. Started probing with a 12v test light and realized power was barely getting to the motors but was good at the master switches. I found corrosion had worked clear through the main 1 gauge positive cable at the flex-point in front of the motor inside the corrugated plastic conduit that protects all the cables/wires until they enter the hull on the starboard side of the transom. Replaced both cables on both motors with 1/0 cable and now the engines turn over like new and start immediately.
Amazing what new cables can do.
 
Good diagnosis! I continues to amaze me how much battery cables can get corroded inside and still look fine on the outside, especially in a saltwater environment.
 
Docksidemarineservices said:
Flex the cable next to your ear if it crackles it is bad........
Click to expand...



Bingo Chris. You are exactly right. And mine were crackling when you bent them sharply. When I cut them in half there was pink and black corrosion all the way through.
I could see this situation being misdiagnosed sometimes.
I was first wondering about my batteries possibly being bad.. and then was thinking maybe my starter was going out.
Nope. Just bad cables.
 
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