Replacing a connecting rod bearing (lower), help please...

[Lepttack]

So I fired up my '81 xs400 last week with no problem. But when I took it for a ride there was this knocking sound comming from deep in the engine, loud too. So yesterday I tore my top end off to find the problem, looks like I got a messed up connecting rod bearing on the right side. After pulling the pistons off, I grabbed the connecting rod and it's got about 1/8" (guessing) of play up and down along with wiggle side to side at the top of the rod (rocking it on the crankshaft).
I've come to the conclusion that I need to replace the bearing, and that I need to split my case to do it. I accept this.
As I was calling around for parts this morning, I got lots of different answers from different places; "2 piece bearing" "2 piece bearing with color code of brown, black, blue or green" "press-on bearing, probably need an entire assembly".
Anybody have expirience or advice with/about changing a lower connecting rod bearing? I searched the site and found threads on "rod knock" and "brake connecting rods", but nothing more along the lines of what I'm looking for here.
This afternoon will be pulling the engine off the bike and peping for a case split, I'll know more when she's open in front of me, but I figure I'd get this thread started and give it time to soak. Thanks for whatever help you can throw my way.

 

[drewpy]

I would replace all the bearings while you are in there, saves you going back in later.

I think that black bearings are the most used now as these bikes are 30 odd years old and need the thicker ones to compensate.

you can work out what size you need by the number on the crank web and crankcase. its all documented in the manual.

 

[Lepttack]

Yup, bearing is jacked, but that seems to be about it. here are a few pictures:

Connecting rods and bearings (right side bearings fell right out, left side had to be tapped out).

Here you can see the wear on the right side bearing. It's almost as if the bearing came loose and was spinning, left side is nice and black while the right is shiny.

How bout some thicknesses you say? First is the good left side bearing, I'm guessing these things started out at 1.5mm. The two after that are from the right side... that would explain the play in the connecting rod.

The right side looked like it had some wear on the side so I threw them in a square to show the unevenness. First one is nice and square on the side, second one must have been rubbing against something on the crankshaft.

Here are the bearings again right next to eachother.

The crankshaft shows about .1mm of wear on the right side. I'm pretty sure I'll replace the bearings on both sides and just leave the crankshaft alone...I can totally live with .1mm of play. So, there you go, that's what I know. Don't make fun of my gloves!

 

[ThePsuedoMonkey]

Mmm, those are some sexy blue nitrile gloves...
I may have spent too much time at my last job!

Also, those bearings are super expensive! I do not envy being in that position.

 

[drewpy]

I've changed my bearings twice and they recently gotten expensive.

I changed them as precaution, nothing else.

 

[Lepttack]

...apparently not expensive, got 2 sets from local Yamaha dealer on order for just about $10 a set. Maybe Im getting the wrong ones, but for $20 to fix my bike, I'll take the chance.

 

[XS-Time]

Wow that is cheap. Mine were much more.
Make sure that price is for two bearing halves and not just one. I'm sure that mine were one bearing half per part number. Eg. you would have to order 4 bearings for two connecting rod big ends.
Also if you want to plastiguage the bearings let me know. My dealer gave me a photocopy of thier service manual with the tolerances for the bearings as the Haynes manual does not list them.

 

[Scorpio1963]

I know this is an old thread but I noticed the one bearing had been spun inside of the connecting rod.Usualy when this happens the journal on the connecting rod becomes out of round also.So instead of just installing a new bearing wouldnt it be better to have the connecting rod honed back to correct form or replaced with another one?