Motorcycle Repair: Opinion Bearing Migration, color dots, main bearing

Question
QUESTION: "Hi Mike,

Sorry, in my first email I incorrectly stated that it was the "left bearing that migrated", please correct this to state the "Right Hand Bearing"  

I started hearing grinding/bearing noises coming from my 1200 sporty, which after removing the cam cover and a detailed inspection, I found that the outer race on the Right main bearing had migrated out approx 1/4 inch and was being grind away by the oil pump drive gear. So I got a couple of questions:

1. Is this common?
2. What type of bearing is the left main?
3. Can the left main bearing be replaced without splitting the cases, as I've managed to remove the bearing retaining clip?

Your help is greatly appreciated.
Thanks
John"


ANSWER: To answer your first question, no it is not common. In fact, I have never seen this happen. The bearing is a roller bearing. The only way to replace it is to split the cases. those bearings a sized to the race and the bearing or shaft might be damaged from it moving.
Good luck and happy riding
Mike

---------- FOLLOW-UP ----------

QUESTION: Thanks Mike, your help is greatly appreciated, seems everyone down under (Australia) is an expert, yet no one can answer my questions.

When you say "those bearings are sized to the race" do you mean the inner or outer race or both, as I believe the inner race is pressed onto the opinion shaft and then ground to size to fit the standard sized roller bearing race and outer race, is this correct.

Thanks Mike.

Answer
What you have to do is measure the inner race and the bearing, then hone the outer race to size it. the bearing come in different sizes and have color dots on them for the sizes. Youw ould have to get a service manual to determine what bearing you need and how much honing you need to do
Good luck and happy riding
Mike