2000 YZ250 Right Side Crank Seal

[Rutrider937]

Hello guys

Not sure which way to install the crankshaft oil seal on the right side crankcase half the clutchside. I have a 2000 YZ250. Some pics of the oil seal i got from the dealer.

When i look at the black side of the seal where there is part numbers it says "IN" "SIDE" not sure if this side faces toward the crankshaft or away?

 

Edited May 25, 2017 by Rutrider937

[Smoking 2's]

Writing in towards motor, it's backwards of most seals. This side in, different bike but the same, however I've not ever seen that green inner. Is that grease of some kind?

[Rutrider937]

No grease that is the way it came factory from the yamaha dealer. So just to clarify, your saying the side with the writing faces the crankshaft, like this? Its suppose to be backwards, compared to the left side crankcase where the writing is showing towards the flywheel?

 

And this is the incorrect way the seal should be facing?

 

Edited May 25, 2017 by Rutrider937

[Smoking 2's]

Is that the left side, shifter side

[Smoking 2's]

This is your bike by the book, it's been a few years since I've done the seals, with that said your trying to keep the clutch oil out of the crank, think of it as a cone and it should make sense. Very little pressure below the piston

[Smoking 2's]

That was extremely irresponsible of me, Sorry! Wait for multiple responses of the same answers.

[Rutrider937]

That is the right side

 

This is the left side

 

Edited May 25, 2017 by Rutrider937

[Motox367]

Black side towards crank "in side"  but honestly with that seal probably work either way 

[Rutrider937]

I picked up the service manual and it says to install the crank bearings with the manufacturers marks facing outward, so i just installed the seal with the black side facing out away from the crank.

[Smoking 2's]

Of the few I've done on dirt bikes, clutch side has always been with the writing in, with that said I've never bought a brand new bike and perhaps they were switched prior to me getting there, good on you for buying the book and getting the proper answer!?

[Rutrider937]

I hope this is correct, being it is stated in the service manual. Also when i look at pictures of others it shows the manufactures numbers facing outward. I bought this bike in pieces with the bottom end stripped. Hopefully everything turns out smooth, really don't want to split cases again.

Edited May 26, 2017 by Rutrider937

[Smoking 2's]

After you posted manual pic, I went in a panic worried about mine, my manual says the same on the yz but on my son's rm85 the right side seal is backwards, my memory has failed me. I say your good to go!

[Motox367]

20 minutes ago, Rutrider937 said:

I hope this is correct, being it is stated in the service manual. Also when i look at pictures of others it shows the manufactures numbers facing outward. I bought this bike in pieces with the bottom end stripped. Hopefully everything turns out smooth, really don't want to split cases again.

It will work don't worry bout it ?

[bikedude987]

I think that's correct, as it's sealing against the positive pressure generated when the piston is on it's downstroke and pressurizing the crankcase.

[Rutrider937]

Now im really confused . . . i went to the yamaha dealer to check if the seal was installed in the correct direction. They are saying the opposite now

They told me to install the seal with the manufacturers markings towards the crank im so confused.

[Smoking 2's]

Follow the book, mine says the same. A parts guy is not a certified Yamaha mechanic, a rookie mechanic may not be a mechanic either. Misprints are possible but not 10+ years apart

[Motox367]

That seal is same on both sides doesn't matter? done many many that way it will be fine. If it had sping on one side then would matter but that particular seal doesn't. Has wipe on both sises.