Any bearing experts? Replacement engine/transmission bearings
 

I plan on replacing all the bearings internal to my '92 XT600 motor (they need it, trust me). Crank, transmission, etc.
The actual Yamaha parts average about $30 per bearing and I know that Yamaha is usually pretty pricey on their parts. Most of the bearings are a standard size so I imagine that I can get high-quality (non-Chinese) bearings from a bearing supplier for cheaper.
I know that even within a given standard size, bearings have different internal clearances for different operating temperatures (Normal, C2, C3, etc.). What size is optimal for the high temperatures a unit-construction motorcycle engine operates in? I have an old Classic Motorcycle Mechanics magazine that states that they should be the C3 design, but I'd like to get some other opinions.

bearings
 

Hi Radbaron,
I went through all this c1, c2, c3 bearing business when I rebuilt my motor. In the end I used genuine Yamaha bearings, just to be on the safe side. Also, a while ago there was a long and detailed thread (On Horizons Unlimited.) on the same subject and from memory it came to the same conclusion. I.E. Use genuine bearings.
Hope this is of some help Paul.

Simply Bearings Ltd ~ Oil Seals SKF FAG TIMKEN KOYO NTN NKE TRULOC Needle Rollers Taper Rollers Rod Ends Oilite Bushes Loose Balls O Rings Grease Plain Thrust - Simply Bearings Ltd ~ Oil Seals SKF FAG TIMKEN KOYO NTN NKE TRULOC Needle Rollers Taper R
They'll ship to anywhere in the world and have a vast stock of special bearings as often used in bike engines. Anything not listed, give them a ring and they can usually find it for you. Very good.

Research and more research
 

I had a similar dilemma and I did two main things.

Get the manufacturer number info off the bearing you are replacing like "KOYO BHKM1730JU" it should be stamped on the bearing. If you can't get the bearing info from the bearing you can try measuring the bearing, internal, external diameter, width and do a google search. It is rare for a bike manufacturer to use a non off the shelf bearing, that is not made by about three different bearing manufactures

Do trawl of the internet for motorbike bearing suppliers. Quite a lot have bearings and models matched up.