Valve Clearance Spec

[Rikugun]

Several times since joining the forum, members have commented on the Yamaha valve lash spec being incorrect and the Haynes manual as having the correct values. Since valve adjustment has come up in recent threads I thought it might be usefull to explore this a bit.
I have 2 questions to start:

1. What are the specs from Yamaha and Haynes? I only have the Yamaha manual (3rd printing Feb '86) and not the Haynes. Maybe there are different specs depending on the print date?

2. How was it determined which set of values are correct? ie is there a service bulletin floating around or a mention of one in the Haynes manual?

My apologies to the long standing members if this has been discussed to death. Since joining I don't recall an in depth discussion and there have been a fair amount of new members since I joined that also might benefit from such a discussion. Maybe there was a discussion and my memory sucks  :( and no I haven't used the search engine to answer my question.  ;D  I'd rather have a forum discussion as it's much more enjoyable. Plus, I need some distractions to tide me over til the weather breaks and my attention turns to riding again.  :)

[Rick G]

Don't worry about bringing anything up , all  the posts before 2008 do not seem to be in the archives. I have a first edition Vision factory manual , a '86 version with the '83 addendum and  a Haynes. I go out to the shed and check.

[Re-Vision]

Rick, I'm finding posts from 2002 ,2004 and more recent.     BDC

[Rick G]

All three manuals , the May '82, the February'86 and the '91 Haynes , valve shim charts are all identicle , so I'm at a loss to see the error.
BDC  I couldn't find any thing earlier than '08 , I'll try again! Thanks.

I found posts going back to 2005, but no earlier.

[Re-Vision]

Found this one.     BDC

So I decided that while Lucky has been holding my carbs for ransom :), now would be a good time to check the valve clearances. I'm using the Yamaha XZ 550 RK service manual (first edition, April 1983), which, on page 2-4, says that the intake clearance should be .11~.15 mm, and the exhaust should be .16~.20 mm. The intake valves on both cylinders are a little tight, so I take a look at the shim sizing charts on page 2-7, to determine which sizes I need to get. Those charts state that the intake clearance should be .16~.20 mm, and the exhaust clearance should be .21~.25 mm. Of course, the charts are formatted using those values, so the blank lines (for "no shim resize required") are at those rows on the charts.

My question, to those of you wiser than I in these matters, is "Which set of values is the correct set of values?" I can mentally correct the charts if necessary, but I want to make sure that I know what the correct numbers are first.

Thanks,

[Lucky]

Valave specs in the Yamaha manual are right (but the chart is incorrect) .11~.15 mm intake, and the exhaust should be .16~.20 mm.

Haynes has it correct.

[Rikugun]

All three manuals, the May '82, the February'86 and the '91 Haynes, valve shim charts are all identical, so I'm at a loss to see the error.

Rick, the error - or discrepancy at least - is between what the shim chart lists as the spec and the spec printed in the body of instructions for valve adjustment. At least in the Yamaha manual. This is described in the quote Bobby posted from '03 by gbranche.

Just so we're all on the same page, my Yamaha manual is as described in gbranche's quote:
IN .11-.15   EX .16-.20 from valve adjustment instructions
IN .16-.20   EX .21-.25 from the shim charts (XS1100 specs BTW, hmmmm)

Anyone with a Yamaha manual have something different? What are the Haynes specs and is there a similar discrepancy between whats listed on the shim chart and elsewhere in the manual?

Lucky, you seem to be contradicting yourself - if the numbers you quoted are right then the Yamaha manual is right and the charts wrong, right!?  Do you have any supporting documentation for the claim "Haynes has it correct" ?

[Lucky]

Man, i gotta watch what I type...  I've fixed my post.

After the discussion in 2003 I Stopped by My local Yamaha dealer & talked to one of the techs (older than me) who brought out a loose leaf notebook with Yamaha bulletins & notes. in it he had a photocopy page of the Haynes manual & a note written in sharpie NOT to refer to the Yamaha manual.  I don't remember weather or not he had anything offical from Yamaha, but for me, that was about as straight from the horses mouth as I figured i'd get.

Also, just my own opinion, but I tend to trust Haynes manuals over dealer manuals.. Even over clymers.  I've seen stuff over the years in their books like shortcuts that come from talking to experienced techs who have worked on these things, in addition to the tools required by the 'MANUAL' written by engineers...  For example the homemade tool to hold the fork dampener is in Haynes, but not in Yamaha's manual...

[jasonm.]

the specs are on the inside of one of the side covers   :)

[jasonm.]

chart, CHART...you don't need a chart...your lash is too loose....get a thicker shim...too tight =thinner shim. You all know the number of the shim is "inked" on the "down side"...I hope.  kindergarden math... kids

[fret not]

Get a metric feeler gauge.  Parts store, here I come. ;)

[supervision]

  My bike from 20,000 to 60,000 miles had a loose tapet sound, i thought, well i must just suck at feeler gauges.  I even took it over to my local friends shop for his inspection. he said their is nothing in your entire valve train that can be making any noise.  phill said go home, look behind the flwheel, sure enough, their was the lose nut, you could move it under the locking tabs, with your fingers.

[Cdnlouie]

chart, CHART...you don't need a chart...your lash is too loose....get a thicker shim...too tight =thinner shim. You all know the number of the shim is "inked" on the "down side"...I hope.  kindergarden math... kids

He...He...I agree with that one Jason!  Never could figure out the why those charts were included  ::).  Kind of like taking the long way home.

[Rikugun]

oops, I goofed. The excel shim chart is in the technical section of Riders of Vision .net No wonder I couldn't find it. It was right under me nose...

http://www.ridersofvision.net/Technical/technical.html

I wouldn't want Cdnlouie to get confused with all that addin' and subtractin'  :)

[jasonm.]

chart, CHART...you don't need a chart...your lash is too loose....get a thicker shim...too tight =thinner shim. You all know the number of the shim is "inked" on the "down side"...I hope.  kindergarden math... kids

He...He...I agree with that one Jason!  Never could figure out the why those charts were included  ::).  Kind of like taking the long way home.

I suspect for the owner who let the lash go WAAAAAY out of spec. FYI, I met just such an XZ550 owner. Whole valve train sounded like goblets clanking together.

[AdvRich]

chart, CHART...you don't need a chart...your lash is too loose....get a thicker shim...too tight =thinner shim. You all know the number of the shim is "inked" on the "down side"...I hope.  kindergarden math... kids

Same here and I use a micrometer to double check the shims and for the ones that no longer are legible.  ;)