Bad crank bearing, AGAIN

[xsfanman]

Helo from Toronto.
I have a totally restored 79 special that runs like a dream.Well, it did till last week.
The engine started to make a high pitch noise that increased with RPM's. Right away I new what it was, ask me how.
Changed the oil and found metal filings
Less than 2000 miles ago I rebuilt the complete engine (when the same thing happened)and replaced all 4 crank bearings with new one's from xs650 direct.
The crank was done by Gord Bush in Toronto.
I know that Gord does excellent work, I have good oil pressure, and the oil galleries are clean. I change my oil every 1000 miles and my filters are clean.
Any ideas that might shed some light, why this keeps happening.
Could it be that the replacement bearings are crap ???

Thanks,
XSFANMAN

 

[Rush2112]

First i wanna say i'm not a bike wrench and many other poster's here have way more knowledge on these machines then I. With that said here goes....generally speaking when bearings start squealing the first thing I'm thinking is lack of lubrication. If a bearing fails that's well lubricated, i have to start thinking alignment incorrect and or thrust tolerance's to tight. Are the mains the only failure??? Case problems? Thinking out loud.... hope this helps and spurs on some others to jump in...

 

[xsfanman]

Thanks Rush2112,
Yes lubrication is good and the cases align perfect .This center bearings have a locating pin, so location and lubrication holes can only go in one way.
I wish we could still get the OEM bearings.
maybe I can find a good used crank nearby

xsfanman

 

[hotdog]

I'm running the Mikes/650 direct mains in one of my cranks with no issues so far, it has'nt done big kms.

What did the last bearing look like...was it all blued up..? As rush has said squealing or bluing is a good sign of no lubrication.

 

[xsfanman]

No bluing, I took the motor apart, and the rollers are all scored on the one center bearing, so bad that they fell out of the cage on their own.
I think the pump is good because the oil was spraying off the valve covers . The crazy thing is that all other 3 bearings and the big ROD ends feel good.

 

[hotdog]

Is it the same positioned bearing as last time that has failed this time.?

You may have a problem with your oil feed to that bearing. Good pressure to the head/rockers does not mean oil feed is getting to the mains. Time to check your gallaries are clean and clear.

 

[xsfanman]

Thanks hot dog, I squirted oil from the pump feed hole and oil comes out clean on all 4 bearing holes.plus the tiny squirters . This morning I'll take the pump apart and see if that sheds any light.




xsfanman
79 xs650 special
07 Kawasaki 900 custom

 

[hotdog]

As you have mentioned the outer main bearing races can only go in one way - how did it look on disassembly, were the outer races lined up & located on the dowels properly..?

I have seen several sets of cases & heard of many more where the dowels have been compressed into the alloy because the outer races have not been properly aligned upon assembly.

 

[xsfanman]

yes they were correct and all the oil holes lined up. I checked my pump this morning and it has more than 0.02 movement (as per xs John) and this motor allways run hot.
So i think I'm going to get new pump parts and follow his instructions on how to re do the pump. I just finished taking the crank apart at the center pin . I'll install a new bearing.
I have a good press I just hope that it will all go back as easilly as it came apart

Thanks for your help guys
xsfanman