Main Bearing Wear Pattern

[Guest]

Overhauling a 1980 GS450L engine with 25k on it. I put in a post about finding flaking bearings, but now I realized I don't know how to interpret the overall wear pattern either. I just don't have any experience with bearing inspections.



Top row is top half, right is right, etc. Aside from the flaking, does that look about normal to folks or not? A guide to bearing wear I was linked to has me worried I may have a warped case (I already checked the crankshaft runout. It was about as true as true could be.), but not having much experience, I realize I may be overreacting.

I apologize for being so clueless. Thank you all so much for the help.

[Nessism]

Looks okay to me. I'd replace the bearings since it's apart but those would have run fine.

[evh]

Nessism is right, those bearings look fine.. normal wear.. that coating you see worn off is the babbit coating.. as long as you don't see deep gouging or any copper coming through.. If that was the case you'd know something was wrong.

[caltrop]

There are various linear scratches along the insides of the shells, but I reckon those are from whatever debris caused/resulted from the bearing flaking. I was more asking about the over-all wear pattern. Thanks for the reassurance

[1980GS1000E]

Don't worry so much. It's only a 450. Now, if it were a real bike......

[Mekanix]

Don't worry so much. It's only a 450. Now, if it were a real bike......

450 or not its still $10 a shell half to replace them!

[1980GS1000E]

I hope he doesn't take his car engine apart.

[caltrop]

its still $10 a shell half to replace them!

I was already planning to replace the shells. I'm just trying to learn all that I can.

[Homie]

There are various linear scratches along the insides of the shells, but I reckon those are from whatever debris caused/resulted from the bearing flaking. I was more asking about the over-all wear pattern.

Looks like a normal wear pattern to me. The flaking and scratches are also normal. Plain bearings (vs roller bearings) are sacrificial - they're designed to wear (the flaking) and absorb foreign material (the scratches) to preserve and protect the expensive parts (crankcase and crankshaft). Probably had a lot more miles left in them. But since you have them out, you will of course replace them. Good work...now back to the garage and put her back together.

[Mekanix]

What do the counterbalance bearings look like ?

12 x $10 for bearings nearly blew me away the first time I priced that :P
I always figured they would be cheap to replace until I started rebuilding.

[tkent02]

I wonder if some cheap car bearings exist that are identical in dimension?

We used Yamaha 650 wrist pins in an eight cylinder Mercedes once and saved hundreds of dollars.