Bearing shells

idkleine wrote:

how would you go about measuring them bsk650?
I agree, its silly not to replace the bearings, unless you don't have $200 for them of course.

There is a bearing Mic, it has a ball end on it rather than flat, it allows you to measure the radius portion. this is assuming you are wanting to measure just the bearing thickness.
The most accurate way to measure clearance is to assemble the cases with the bearings and without the crank, very carefully measure the bore of the bearings, then subtract the crank size and you will get a accurate clearance, do this in several places on the bearing.
I use a hand held set of inside micrometers not the snap ball type.

I dont like pasti gauge, I have found that you can "change" the reading by doing little things during the torque process, so I dont trust it. granted I was trying to see if I could make it give me a false reading, but the point is it can be manipulated

makes sense. Except wouldn't the clearance be the bearing ID minus the crank journal size divided by 2 since there has to be clearance on both sides? Of course if Im going to order new bearings this still doesn't tell me what "color" to order. I wish they just listed the inside diameter somewhere. It seems to be truly obscure info! I have fired of a bunch of emails to parts suppliers and engine builders. We will see what happens. Thanks for your responses.

Determining the bearings you have can be a guess, the chart shows what bearing to buy for a given clearence. Its sometimes nessecary to assume you have the (std) size wich from the factory is 90% of the time going to be Black for the rods and Blue for the crank. That isn't always going to be the case but if you have to start somewhere and don't have a reference you can do it that way. Either way you need to veryify clearence when you put it back together. The manual gives you the insert type based on two measurements IIRC. So measure the rod bore and the crank journal and it should put you on the chart, same for the mains. I have a later model year manual if you post those measurements I can show you which inserts you need. Once you see how they do it is is very simple.

Ok. So I will need to bolt the case halves together to measure the bores? I did measure all the crank journals but not the bores so I will fetch a inside micrometer tomorrow and get those inside measurements. Thanks for the help.

You said you have the manual? Look on page 6-50. There are marks on the crank, case, and rods. If the marks are not found in those locations shown on page 6-50 then they have "no marks". In wich case the correct rod bearing is "black" and the correct main bearing is "blue". This is the change from the 1980 manual where IIRC there were measurements involved with the rod bore etc. For the life of me I don't know why the change was made but they do things differently on your engine.

All right. My case clearly has the "0" marks in 4 of the 5 indicated spots. I left the crank at the shop so I will check it tomorrow. And as for the rods, they only have this marking which appears to be a light colored "K" with a circle around it. Im guessing this is irrelevant and will consider this as "no" mark.

The letter "K" is an alinment mark so you put the rod back together correctly. The circle around the K I believe is the "O" mark. I had letters on my rods but did not have that circle around them.