Valve lobe position - valve clearance

[Guest]

I didn't wanted to hijack Stigys post.
In short: bought an gs550 from 1980 with 62.000km

3 cylinders have 120psi and #4 only has 90psi. I guess piston rings which got stuck.
Waiting for new intake o-rings. Took out the sparkplug and poured in some Marvel Oil to see if it loosens up carbon and stuck piston rings. (Engine runs fine)

When checking the valve clearance I saw that there was quite a change between the cam lobes being in vertical or horizontal direction. See below (v=vertical position towards exhaust or intake. H is horizontal position, upwards) figures are in mm

C#1 ex V0.16 H0.11
In V0.02 H0.09
C#2 ex V 0.08 H0.11
In V0.06 H0.01
C#3 ex V0.06 H0.10
In V0.09 H0.05
C#4 ex V0.10 H0.03
In V0.03 H0.11

I am amazed by the difference, is this normal? Since according to the manual it shouldn't matter. What measurement should I use?

Thanks, Luuk

[Big T]

The factory service manual says it shouldn't matter?

[Luuk]

The factory service manual says it shouldn't matter?

That's what I saw as well. But since the differences are quite big.. What to do with the shims. Replace so the lowest number stays in spec?
Cause if I only would have measured the horizontal positions, the intake of #4 is 0.11mm. Therefore the shim needs to be increased with 0.05 which is not possible since the vertical position only measured 0.03mm
Or am I getting confused?

[Nessism]

There are dozens of threads in the archives about this. Basically, if you point the lobe away from the valve the adjacent valve will be depressed and pushing up on the cam, which skews it in the journal clearance. Positioning the cams per the Suzuki method will result in tighter clearances than pointing the cam away from the valve for this reason.

Does it matter much? NO. But if you use the lobe pointing away process I'd target the top end of the clearance range, and even extend it .04mm.

[Steve]

It can be decoded as "the manual says it does not matter" but that is not what they intended.

If you look at the drawing, you will see lobes pointed up and horizontal, but read the text that is next to the picture.





Also be sure to check out THIS THREAD. Good discussion about valve adjustment. I detail the procedure that is outlined in the factory manual starting in post #17.

.

[Luuk]

Thanks guys for the explanation. I noticed that the Dutch Suzuki workshop manual is missing some vital information. I will stick to the digital English version and pdf manuals from Cliffs website.