Cam sprocket "play?"

[BBMS]

I have an exhaust bolt broken, and need to remove the head to take to a machine shop for removal. Thanks to the excellent tutorial by B-dub on base gasket replacement, I was able to tackle the project today. I did have trouble removing the cam sprocket by securing the bottom bolt, and having this chain maintain tension ... the cam sprocket would slip, but I loosened the chain, and removed the head with the sprocket still attached.



The sprocket has play in it, and I'm not sure it should have any. Does it?



Thanks! Mark

[elime]

I am not sure what you mean by play but if you mean the sprocket rotates and the camshaft doesn't (or vice versa) the answer is NO! The sprocket and camshaft should be solidly locked together.



If you mean there is a slight rotation of the camshaft sprocket caused by a chain that is first slack on one side the loose on the other and you rotate the sprocket slight and the tight side becomes and the loose and the loose side tight, that is OK.

[BBMS]

I am not sure what you mean by play

Side-to-side movement, as if a bearing were worn, perhaps the collar?



Thanks for your reply! MY

[elime]

I had mine apart about 2 weeks ago and there was very little play in the bearing. A little is normal because you have to leave room for the oil. My TW has 20K miles on it.



There is an aluminum collar / bearing that you can pull out along with the camshaft using a slide hammer. If you have any doubts it might be a good time to replace it. Part number: 90387-255F3-00 for a 2000 TW but I bet they are all the same. $15.75 plus S&H from San Jose Yamaha. Some have replaced the bushing with a ball bearing but I don't know what size to use. Someone else will have to chime in for that.



Good luck!

[BBMS]

Thanks!

[elime]

I decided to replace the intake valve on my first TW and remembering your post about cam shaft play I took some pictures.



Here is the camshaft along side the aluminum bearing I was talking about.







This is the bearing on the camshaft. There is very little play. It is actually kind of tight but may loosen as the engine gets hot.







And here it is in all its glory assembled in the head.







I have more pictures but this is already overkill.

[jckosnow]

for newbies like me the pics are always appreciated

[BBMS]

I, too, appreciate the pictures! The manual's pictures are not as easy to relate to. Thanks again! Mark

[elime]

I like posting pictures. Here are the two I left out figuring they weren't necessary but what the heck, here they are!



This is the camshaft in the head w/o the bearing.







Here is the aluminum bearing sitting on top. It is a very tight fit putting it into the head. One time I heated the head with a heat gun, froze the aluminum bearing and moved very fast and it slipped right in. I tried that today but didn't move fast enough and had to use a piece of wood and a small hammer.