Check Your Valves !

[Kenny]

  I just finished some delayed winter work on our 83.I had some valve cover leaks and checked the intake & exhaust valves while I had it apart--not one was correct, they all had less clearance than required.Most needed shims two sizes smaller. I bought this bike when it had aprox. 20 thousand miles on it & didn't bother to check the valves as the history showed they had been checked at 15. It now has 40 thousand miles on it and I am going to monitor it for further movement more often.
                  Cheers Ken S.    

[Walt_M.]

Interesting, it has been 4K mi and several years since I did mine last and I think I changed 4 shims. You might have to re-synch your carbs, I did. Had you noticed any 'popping' from the exhaust when decelerating? I had not noticed anything unusual about valvetrain problems except, I think Bruce dropped a valve a week or so ago.

[jasonm.]

I have told others what you have seen. Valves tightening up. This can cause burned valves.  I think I had 5 or 6 tight on my '82. Corrected that. My '83 only had one or 2 loose 10k ago. Corrected also. "Better loose than tight."

[rick_nowak]

too loose leads to excessive noise and reduced performance.  if loose the valve is not opening all the way per specs so less pumping of fuel/air mixture is taking place.  also, the "quieting" ramps on the flanks of the cams are not being used to their max.
always be aware of the ambient temps and follow factory recs for clearance at a particular temp.

[jamesrransom]

   usually it means the valves have pounded the seats deeper into the head, or the seats are worn down

[jasonm.]

Mine are always in spec. but If you don't have them perfect then...Which you you rather have? a little loose with a tick once in a while or too tight ...burn a valve, loose compression and replace the valves. Old BMW's follow the loose rule. Which also allows more contact time with the seat to cool the valve...especially the exhaust.

[rick_nowak]

i didn't know that old bmw's had a problem with burning valves as long as the lash was set to spec.  in fact, i'll bet that they don't have a problem here.  these engines are reputed to live forever!  they were built to an old recipie: conservative specs, quality materials, quality workmanship.
i would allow that the odd 1/2 thousandth more open will do no harm, but i will stand by my earlier assertion that it will lower performance and increase noise.  i'll also say that delibertately increased clearance will cause valve train components to wear out more quickly not more slowly due to impact loadings not designed into the components.  as a general rule the engineers that design and specify this stuff know their business and do a very good job.  the problems come in when the beancounters nix a design element as too costly and the further compromises enter in.  there are some stellar examples of this thinking in the vision-charging system, starter shaft seals, starter clutch fastener system, carbs(maybe).  and then you have the good ideas that go wrong carbs(probably), tank styling(rust pockets anyone?)

[Kenny]

 Rick,
     Don't rush out and put any money on the "old BMW's" not having any valve problems, man they've got no shortage of valve woes! I have an 84 R100rs and the valves gap on the exhaust are continually tigthtening up. Their are all kinds of fixes different seat material (Stellite) different grinds (three angle). This problem really reared its head with the change from leaded fuel to unleaded. With exhaust valves its has a lot to do with heat transfer.
           Cheers Ken S.

[rick_nowak]

i agree.  i thought about and should have said pre-unleaded fuel.  the lead was a great lubricator.  also a really good poison.

[joevacc]

I just had my valves done this year. They have never been ajusted. They were also tight.  Three in the front cylinder and one in the rear.

I sent it to a dealer here because I didn't have the valve tool.

Do you guys have the Yamaha tool?  Do you need it?

I hear that it is a real pain in the butt to do the valves on the V, is it?

JV

[Rick G]

Don't believe all the propaganda on Beemers.  The valves on a V are not a 15 min job and you do need the tool.

[gbranche]

In my experience, one only needs the tool if any of the shims need to be swapped out. The tool is not necessary simply to check the clearances.

Of course, if you're going to open things up that far, and discover that you'll need to swap one (or more) of the shims, you'll be disappointed that you have to order, and wait for, the tool.

I bought one a year ago via my local Yamaha dealer. They were still available then. Don't know about now...

Greg

[silicon_toad2000]

I'll be doing the valves on mine sometime soon, anyone tell me what the clearance is?
My little mistrusty steed is an 82 XZ550R.
All the valve clearances I have done before only require a spanner and a screwdriver (once the rocker covers are off).
Is that the deal with these?

[Walt_M.]

The clearances are set using shims. You will need the special tool to change the shims if you need to adjust. It fits on the hex on the cam and pushes the shim bucket down so you can get the shim out. You will need a manual to figure the shims you will need. The tool may still be available from Yamaha.

[gbranche]

I discovered that the chart in my Yamaha manual was incorrect. I produced an Excel spreadsheet with corrected values for my own use, and have placed a copy in my Mac.com file sharing area:

http://homepage.mac.com/gbranche/FileSharing.html

Download the "XZ550ValveShimChart.XLS" file.

Greg

[travis_mandeville]

I was able to make a valve shim tool from the picture in the manual, also made a valve spring tool that worked really well

[PeteN]

Well at least the Vision is much easier to adjust than any other shim and bucket type valve system that I've seen.  Usually you have to remove the cams!

Thanks Greg for the nice charts!

Travis, any chance of more details or pics of your homemade tools??

[h2olawyer]

I believe the valve clearance chart in the Haynes manual is correct.  I may check Greg's chart to my Haynes and Yamaha manuals just to be sure.  Thanks for doing the spreadsheet work for us Greg!

As for easy valve adjustment, a while back someone posted that the next time they did it they would seriously consider pulling the engine for easier access.

Check Lucky's site for instructions on making a valve shim tool.  He's got a good plan for using a 22mm 6 point wrench and a grinder to make one.  Address is  //www.xz550.com/art.html  look for the diagram in the third row from the top, second picture from the left.  Click on it and it enlarges to full size.  Drawings are not to exact scale but the critical measurements are there.

I think the tool is available from Yamaha again.  It was discontinued for a time but there was another post in the forum last fall about it.  Guess it's time to go back and refresh my memory.

H2o

[Lucky]

Drawings are not to exact scale but the critical measurements are there

you don't like my artwork Drippy? lol  ;)

just playin..

[h2olawyer]

Sorry Lucky - the artwork is fantastic!  You should see the poor job I do with that sort of thing :D  Guess I could have meen more diplomatic about how I said it.  Just being the typical lawyer for a minute.  ::)