Logo
FULL SITE MENU

BF90D flywheel

H

hughj555

New member
My flywheel teeth have worn out and I am about to replace it (BF90D). It is on the bottom of the motor so it is quite a job. I have the honda manual and it looks like a lot of work but I am up for it. Is there anything I need to be concerned with or must check when I do this job. Looking for some techs to give some advice based on their experience on these engines. Also any thoughts on why the flywheel may have worn out? Starter seemed OK.

Thanks in advance!

Hugh J
 
Talk about an involved job !---First you remove the lower unit, then the lower mounts, then the exhaust housing , then the oil sump.------Now you can access the nuts that go through the oil sump to remove the powerhead.----Involves a couple of expensive gaskets as well.----Good luck on the project.
 
anything about the job that i really need to know- like something that is easy to destroy if you don't know about it? It will certainly be a project!
 
You did not say if there has been water in that area or not. If water got in there, then the wear will be from rust, etc.

I would also replace the two seals #20 http://www.boats.net/parts/search/Honda/Outboard%20Engine/2007%20and%20Later/BF90DK0%20LRTA%20/MOUNT%20CASE/parts.html and the shift shaft seal #38 http://www.boats.net/parts/search/H...nd Later/BF90DK0 LRTA /SHIFT SHAFT/parts.html

The shift shaft seal has been the source of water in some of the 90's that are not rigged correctly and water is forced up through the seal.
I would also remove the sealing bolts, #1 http://www.boats.net/parts/search/H...Later/BF90DK0 LRTA /CYLINDER BLOCK/parts.html on the underside of the powerhead and seal the washers on both sides with a good RTV or Hondabond 4. These tend to rust and leak oil. If they are rusty, I would replace them.

Otherwise, follow the manual and do not try to shortcut it. On the other hand, sometimes will will tell you to take things off, that you do not really need to take off for what you are doing. Just think it through as you go.

Pay attention to the instructions on putting it back together. Note that most of Honda gaskets go on without any type of sealant, however, you will need to use some in a small section of the mount case gasket (under the powerhead). If I recall, there is also some you will need when reinstalling the midsection.

Be sure to loosen and install/torque the mounting bolts in the order specified in the manual.

So, be sure to read the manual.

One last thing....take a lot of pictures as you take different sections off. Especially, when you have to remove hoses and wiring. The pictures will save a lot of time looking things up in the manual when you need to know what is routed over what. I usually take closeup pictures all around the motor before I start and as I uncover different layers.

Mike
 
Thanks to all! I will let you know how it turns out. I will replace the parts as recommended. Taking pictures was a great idea- how simple but yet so helpful. This is exactly what I was looking for. I hope I can help out in the future.

Hugh
 
Got to the flywheel and it is very rusty. The seals must have leaked! The flywheel bolts are corroded also and I can't get them loose. Does anyone have any ideas? They appear to be 12 point pattern and I am rounding the heads off. Any tricks would be appreciated. Thanks in advance.

Hugh
 
Metric 12 point sockets are needed.-----Since they are in bad shape you might as well weld a nut onto them in order to remove them.--Order new bolts.
 
hughj555 said:
Thanks, i'll give it a try
Click to expand...
Had to grind the heads off the bolts and the remaining studs came right out. Also found the cover over the upper mounts was corroded and had to replace. Finally got parts and everything went back together fine. Thanks for all your help. I hope I can return the favor one day.
 
hughj555
CONGRATULATIONS! That is a MIGHTY big job for ANY good mechanic so, if you are just a DIYer boat owner TCB (takin care o business) I tip my hat to you even higher!
 
Before I bought another used Honda outboard I would pull the starter off and look down the hole. I performed this inspection on my two Honda 90's and got lucky. Clean. When I performed the same inspection on my parts motor, it was pure ugly. Salt water was down there for sure.

Good work on your outboard, I bet you knew the motor a LOT better now!!!
 
Back
Top