Cam chain cavity seal? Athena

[46and2]

I havent done an intro yet but, hello to everybody. I have been a lurker for a while and own a 78 xs11. I have a question about the cam chain cavity seal.

Does this go on over the head gasket ? The Athena gasket kit I got did not come with one? Am I supposed to use the old one? Or does this style gasket not require it? Any help would be greatly apprecited. Bob

[bikerphil]

Welcome. When replacing the head gasket, that cam cavity seal is no longer used. Just leave it out.

[blue giant]

Welcome to the board.

It is to be left out after a rebuild or head removal.

HTH

Paul

[46and2]

Thanks.

Thanks a million! That is good news. I had a feeling and almost put the head on. But stopped and figured I better ask. Back to work I go. I will post some pics of the rebuild soon..

[bikerphil]

Careful when re-installing the timing chain. These motors run backwards (clockwise from left timing plate) as opposed to most other motorcycle engines.

[46and2]

Careful when re-installing the timing chain. These motors run backwards (clockwise from left timing plate) as opposed to most other motorcycle engines.

Im a bit lost. Do you mean for rotating the crankshaft. always go clockwise from the left. I think the book says the same thing in different words. Thanks again.

[bikerphil]

crank rotation

Yep, you got it. Just making sure. Glad you have the manual.

[fredintoon]

Yeah, the engine runs backwards.

Im a bit lost. Do you mean for rotating the crankshaft. always go clockwise from the left. I think the book says the same thing in different words. Thanks again.

Hi 46&2,
not the first time I've posted this but it bears repeating.
An improvement that Japanese Mfrs get little credit for is standardizing primary reduction via a pair of gears coupled with an all indirect twin shaft transmission. This lets the engine run forwards while the clutch runs backwards and the final drive sprocket (or bevel) runs forwards again. Except for the XS11. They kept the twin shaft transmission but went to a Hyvo chain drive for the primary reduction so that great hulking crankshaft has to spin backwards and thus precesses the wrong way on corners.
One doubts that Yamaha's designers had even heard about the 1930's New Imperial, but New Imperial's designers also replaced their primary chain with a gear drive. Alas that those two gears drove a British concentric shaft transmission where the clutch and output shaft have to turn in the same direction. So New Imperial's engine also had to run backwards and New Imperials also had a reputation of having "interesting" handling.