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Crankshaft bearing removal and installation

6661 Views 6 Replies 4 Participants Last post by  Exmoz

SO, I have my 2011 CBR250r engine apart and it looks like the main crankshaft bearings are toast.
This engine rebuild was the result of an engine stop due to an oil filter put in backwards (yes, this was my bad).
These bearings are plate type parts (each bearing is made up of two half-circular plates instead on roller bearings) and only cost $30 for the parts. The hard part is replacing them!
I called a local Honda dealer to see if they would remove and replace the crankshaft bearings because a special tool is needed. The guy said they could not work of "loose" parts because of warranty issues. Sounds like a bunch of crap, since my warranty is over and done with.
Does anyone have experience with removing and replacing these bearings? Any tool tricks?
I am in Portland Oregon and need to find someone local who can help out if I can't do this myself.

Also, while I don't have time to share the whole engine rebuild in a blog post, I am happy to answer any questions regarding the engine rebuild.

Any help would be appreciated.

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Hi Steve,
You can press the old bearing shells out with a socket but you definitely need the special Honda tool to install the new ones. I've rebuilt a few engines now and there's really no way around it. The tool clamps the shells and then allows you to press them in (using a hydraulic press) to the proper depth. If you have access to a lathe you could make your own tool for a lot less than the $300 Honda wants for it...
Good luck.
Steve, take it to a machine shop with the critical specs (probably depth). Ask around about a machine shop with old timers with experience. They can probably fab something to get the bearings in properly.
The Honda tool uses a two-piece collar that bolts together, flexing/compressing the bearing shells slightly so they'll fit into the main bearing bore. Then the plunger fits the ID of the collar perfectly and is just long enough so that it pushes the shells to the right depth when you seat it. It's also important to line the shell ends up with the arrow embossed in the case so that the holes in the shells line up with the oil delivery holes.

I can spec the tool if that helps. As stated before it wouldn't be hard for a machinist to reproduce it.
Thanks for the replies and sorry for not responding for so long.
I did get the parts and I did find a hack for installing the main bearings.
I used a hose clamp to compress the two halls of the bearing. Then I inserted a large socket into the hose clamp along with the bearing.
I used a long bolt running through the socket, down through the bore and through a piece of wood 2x4 that I drilled. I then gently tightened the bolt (two washers on top of socket). I periodically checked to see if the bearing was seating properly.
They went in without much trouble.
A ******* move, I know, but the bike is back together and is running well.
We will see after a few hundred miles and I get it above 6k RPMs and see if she holds.
Hey @Steverides123 How did that rebuild go and how did it hold up.
Currently also rebuilding my engine,here, my bearing are also toast with piston and Crankshaft.

Would you advise I spend the money and buy a casing with the bearing factory installed?
Can get it for 7000india rupees, but shipment cost will be high due to weight.
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