Valves or Guides

[jfmerk]

Hello again!
I am back into restoring my 78 E with renewed vigor and excited to make a great deal of progress this summer with my goal of creating a bike that looks just like the one on the XS11 home page!!! In my last post... almost 4 years ago! I mentioned that my engine was torn down and in need of some valve work. I've dug out all the parts from storage and I have the head at a very reputable engine shop and they tell me the exhaust guides should be replaced. The exhaust valves did feel very much more loose in the guides than the intake valves did. The seats and valves are pitted pretty bad too. The shop indicated the new guides are on back order for "who knows how long" and if I can find my own they'd install them for me. As I look for exhaust valve guides, I am finding 1st oversize only. Is this typical? This means I would need to buy OS valves too right? Should I be looking for OS valves and just have the existing guides reamed?

Looking forward to more discussion and sharing my progress!

Jeff

[b.walker5]

4 years between posts.., man, you really think about things before you reply don't you. Good to have you back. I wasnt aware there was an oversize in valve guides and it doesn't make sense to me that there would be. Surely an oversize guide would be only bigger on the OD and would require reaming out the head, because why would anyone buy guides with a larger ID when all that would be needed is a ream out of the existing guides. I might be wrong though.

[jfmerk]

After reading through my service manual, I think that in the case of valve guides, an oversize valve guide actually means a valve guide that is slightly smaller than 7mm and must be reamed to fit the existing valves.

Can anyone confirm that?


Jeff

[Bigleo]

guides

Hi, I went through this recently. I bought the oversize valve guides and measured them. The oversize was on the outside diameter. I'm guessing they were designed this way to allow for metal being scraped out of the head when the old guides are pressed out.
Leo

[xssidecar]

Hi all.I hope I'm in the right area for posting this question.Anyhow I have a problem with my 1980 XS1100g in that I have bent inlet valves from a broken tensioner guide.All fixable but living in NZ nothing seems to exist here for XS's.Having scoured the net I just cannot find any suppliers for such things as valves and guides.Can anyone help with any names please.
Thanks a bunch.

[Yard Dogg]

Maybe someone on here has a good head they can sell you. May be cheaper than a machine shop and parts.

[bikerphil]

Here is a supplier for valves for the XS1100 engine, they are in the USA, scroll down to bottom of the page....

http://www.newmotorcycleparts.com/mo...ts/valves.html

[MPittma100]

Valve guides

I am wondering if the machine shop can put in the thin-walled bronze (automotive) guides. These would fit inside the existing worn guides.

I know that replacing guides in an aluminum head is pretty tricky as normally the head has to be heated to properly release the old and install the new guides.

I have had worn (bronze) guides repaired using the thin-walled guides because the factory guides were too hard to remove.

May ask your machinist about this.

I have 4 new Yamaha intake valves (3H7-12111-01) in the factory packaging if you are interested.

MP

[Yard Dogg]

I don't know how hard these are, but I've heard of people using dry ice to remove them. Just take a small piece of it and set it on the guide,then tap it out. To put them in, you would cool the new guide in the freezer, then heat your head in the oven a few hundred degrees. I know it works with cast iron, not sure if it would hurt the aluminum.