Topic: Changed my oil and cleaned the trap/catch & oil pump.. found this. CB750 K5

[Speedngheadphone]

Hey, was cleaning my oil pump and screen and found this in the pan on my 750 K5..

What is it?

[shinyribs]

Looks like a bit of trouble. It actually looks like part of a bearing cage. Bike making any funky noises? If not, maybe debris never cleaned out from a repair done back in the day???  Whatever it is/was, hope it works out for you.

[Markcb750]

Yes, sure looks like a bearing cage, would be from one of the transmission shafts...Cant believe its not screaming I'm broke when you run it. 

Hard to believe anyone would leave that in the case if it was replaced by a PO...Strange one, let us know what you find.  I would not run it till I understood the problem 100%.  If a ball bearing has come apart like that damage to the case is probable.

[Speedngheadphone]

Yeah, I haven't run it since the oil change when I found this.  I've been running it this summer with no real problems.  It has a clunky shift here and there, as I'd guess most old CB's do.   But after finding this, I think I'm going to have to find a place to tear the engine/trans apart and see what it looks like.

[scottly]

How about a pic with something to show a scale? Penny, ruler, etc.

[Raul CB750K1]

If it were from your bike, it is already too late. It is not the kind of thing that go wrong and you don't notice. If it were from your bike internals, it would already be too late. It is not just "wishful thinking", but if nothing seem to be wrong with your bike, chances are they are from a previous repair.

When my cb350 broke a cam chain, I was unable to find half a link plate. No shaking, flashlight, magnet, would catch it from underneath the splash plate. I decided it was small enough to remain there for ages. If someday somebody tears the engine apart and finds it, he will get puzzled about where did it come from, and then I'll laugh in my grave.... :-)

[dave500]

thats a big chunk of #$%*,im with shinyribs that its a left over?

[Kevin D]

Separator plate, bearing cage.

[PeWe]

Yes, it must be part of the ball bearings. My engine is apart and the bearings are the only parts that look similar.
It might be the bearings on clutch axis or the gearbox axis. Anyway, the engine must be taken out and opened. It might be enough to open from beneath and avoid open the head, remove cylinder with need of new rings etc.
If the engine has not been opened, repaired for a while it might be time for an overhaul that will end up in valve/seat job, rebore with new pistons, general bearings upgrade.....

The domino effect of this will be big bore, high compression pistons, hotter cam, ported head, etc, etc. I know...exactly what happened to me many years ago and maybe now once again when restoring from 22 years hibernation.

[lucky]

Yes, the engine will have to come apart.
Just be glad there is not a big hole in the cases, or you would be looking for a new set of cases or complete engine.

[Kevin D]

There is one bearing under the shift mechanism that can be changed without pulling the engine. It is inside the piece with the four screws.

Cant believe its not screaming I'm broke when you run it. 

+1

[Don R]

I just had a valvetrain bolt go through the inside of the crankcase of my race car engine, trust me it ain't a pretty sight. Hopefully most of your pieces just fell into a crevice and stayed there. Unlike my 567" big block the honda has places parts can fall into and rest there until they are removed.

[DH]

How about a pic with something to show a scale? Penny, ruler, etc.

+1.......   Maybe the clutch lifter bearing?