Split valve collar

[Fangit]

Anyone seen this before? I presume the head needs to be removed to replace the collar?

[rodekyll]

No, there are tools that let you hold the valve with compressed air while you change out the top cap.

[rodekyll]

The hydro recall toolkit does those collars with the head in place.

[acogoff]

    Mind you I have never used this method on a Guzzi, But on airplane engines feeding a length of clean nylon rope into the sparkplug hole and then bringing the piston up toward TDC on the compression stroke may hold the valve closed enough to get the keepers out. Requires several hands.

[rodekyll]

Injecting high pressure air inn the spark plug hole does the same thing.

[Wayne Orwig]

Looks like an alloy top from a hydro update.

[rodekyll]

Is there an appropriate spring compressor ?

  Dusty

Yes.  I've got it around here somewhere.  It's a kit.  There's a framework that bolts onto the head and other jiggers to do the levering.

Looks like an alloy top from a hydro update.

Good eye.  That's exactly what it looks like.  A little wider shot and we would have seen the adjuster too I'll bet.

[56Pan]

    Mind you I have never used this method on a Guzzi, But on airplane engines feeding a length of clean nylon rope into the sparkplug hole and then bringing the piston up toward TDC on the compression stroke may hold the valve closed enough to get the keepers out. Requires several hands.

I've used this method many times.  It works fine.

[Antietam Classic Cycle]

Looks like an alloy top from a hydro update.

Roundfin - look at the rocker cover gasket shape and the steel rocker support. 

[Vasco DG]

Looks like an alloy top from a hydro update.

Yup, but almost all Guzzi twins since some time very early have used alloy caps. It ain't a hydro because it's a roundfin and because of that the Hydro Recall kit wouldn't work, (Stud spacing on the cylinders and therefore the tool are different.).

It's an odd failure for sure but not insurmountable. The 'Rope Trick' is a good idea but really? Getting the head off a poxy old roundfin is so easy why would you bother not just pulling it and doing it on the bench rather tha busting your arse frigging around trying to get it off in-situ.

Pete

[Fangit]

Thanks gents. It's from a 1984 1000SP.

[rodekyll]

Missed the round part.   :-[

No, the hydro tools won't bolt up.   :(

[Chuck in Indiana]

Yup, but almost all Guzzi twins since some time very early have used alloy caps. It ain't a hydro because it's a roundfin and because of that the Hydro Recall kit wouldn't work, (Stud spacing on the cylinders and therefore the tool are different.).

It's an odd failure for sure but not insurmountable. The 'Rope Trick' is a good idea but really? Getting the head off a poxy old roundfin is so easy why would you bother not just pulling it and doing it on the bench rather tha busting your arse frigging around trying to get it off in-situ.

Pete

This. I've used the rope trick many times on airplane engines, too.. but it's a little more labor intensive on an airplane engine to pull a "head."  ;D