Yamaha valve adjustment chart wrong?

[odie1]

OK, I'm looking at the Yamaha factory chart for valve clearance adjustment.....the exhaust chart don't make any sense.:confused2:

The blank row for measured exhaust clearance which should indicate "normal" range has been observed and thus no shim replacement needed is on the 0.16-0.20mm line which is outside of the published spec of 0.26-0.30mm for the exhaust valves. And if you measure the valve to be in the correct .26-.30mm range the chart then tells you to change shims:bang head:

The intake chart makes perfect sense since the blank row falls on the 0.11-0.15mm line

 

[tugla]

time to call sean as i havent got into mine to check valve clearance yet, due soon here.

 

[maleko89]

I don't use the chart. I manually calculate clearances and shims needed. I believe someone published and Excel spreadsheet not too long ago. It's on the forum somewhere.

 

[MaxMidnight]

Correct - it is wrong in the Service Manual; Mr Haynes however noticed the cock-up and got it right.

I have a picture below - poor quality but possibly enough to get you by.

It is also in my 'Bits and Bats' album on this site.

I can e-mail a decent one if it would help.

 

[odie1]

everything seems to be in increments of .005mm.

i wounder if you could just pencil in the missing 0.16-0.20mm row and then "cut" out the correct 0,26-0.30mm row and "paste" it at the top of the chart?

Now that I start looking at the charts, it's clear that the chart is all in .005mm increments and the Shims are all in .005 increments. Thus meaning you are only gonna adjust your valves up or down .005 at a time.

So if you are at the extreme end of the correct range for a given valve, but still within tolerance, changing out a shim will not move you more to the "middle" of the correct range but only out of range. If you are "barely" in tolerance you ain't gonna get it any better....unless someone makes "off-set" shims so to speak...