B6000 Decompression Valve Adjustment Procedure?

[warmblood58]

A good day and well . . . . Adjusted valves and while I was at it, replaced orings in decompression valves that sit in valve cover. What is the adjustment procedure? I see how the little cams act on the top of the valve springs -I am guessing that screw is turned down until it just touches top of valve/valvespring and then locked with nut? Replaced fuel lift pump (mine was dead) and installed new oil pressure sender which did confirm my old sender was toast (light off now!) Forgot that I turned off fuel valve while I swapped out fuel pump - tractor started right up and then died after running for 4 minutes - my first thought was I had sucked air when I swapped out fuel pump but then realized I sucked air because fuel valve was shut off -dumb move. So tomorrow, I will be cracking fuel lines to bleed air out - used to do this on Dodge and Mercedes diesels - hopefully this will be just as easy on the tractor.

 

[North Idaho Wolfman]

If the valve was shut, it didn't suck air, it just didn't deliver fuel.
You should be able to open the valve and procced with starting it without bleeding or draining anything.
As far as adjusting the decompression linkage, follow the WSM.

 

[warmblood58]

If the valve was shut, it didn't suck air, it just didn't deliver fuel.
You should be able to open the valve and procced with starting it without bleeding or draining anything.
As far as adjusting the decompression linkage, follow the WSM.

Thanks Wolfman, I'll spin her up this am and see what I get - I'll see if I can access a shop manual online somewhere. Just looked at quite a few WSM's online -have yet to find a procedure that describes adjusting the decomp cams -my guess based on what I see with valve cover off is in neutral/off position, tip of adjustment screw should just make contact with top of valve -when lever is pulled, cam rotates and slightly decompresses exhaust valve to allow for air leakage

 

[North Idaho Wolfman]

https://www.kubotabooks.com/ has both the OPS and WSM
And the Unloaders should not touch or it will rattle to high heaven, there will be a set gap.

 

[warmblood58]

https://www.kubotabooks.com/ has both the OPS and WSM
And the Unloaders should not touch or it will rattle to high heaven, there will be a set gap.

I still have yet to find anything in the WSM or otherwise on the clearances for the decompression valves and a gap which would allow just enough pressure on the exhaust valves when the cams are rotated - weird!

 

[Russell King]

I think it’s not that important honestly. Look at how much the lever can move the “decompression valves” and I think you should see that just getting them close to touching will be fine. Then use the lever and make sure you get the valve open to prevent compression and call it good. You probably don’t want to force the valve open too much and cause interference with the piston either so you can probably check if that is even possible.

 

[warmblood58]

I think it’s not that important honestly. Look at how much the lever can move the “decompression valves” and I think you should see that just getting them close to touching will be fine. Then use the lever and make sure you get the valve open to prevent compression and call it good. You probably don’t want to force the valve open too much and cause interference with the piston either so you can probably check if that is even possible.

That is kinda where I am at in my thinking. I think if I can screw valve contact screw down until it touches valve screwing by hand, and then back off a 1/2 turn, I would think I would be good to go. I have a new valve cover gasket that needs to be installed - this would change the height too somewhat

 

[Lil Foot]

From my B5100/6100/7100 service manual:
(for what it is worth)

 

[warmblood58]

From my B5100/6100/7100 service manual:
(for what it is worth)
View attachment 95173 View attachment 95174

This worked perfectly, thank you so much Lil Foot!