i just can not find my Saturno list
Only the one from the Nordie and she has no decompressor.
But a little plug to close the bore.
There is a O-ring listed.
So that might be the same as on the decomp shaft
The bad thing, the shaft is secured by a little pin located in the sealing area of the head cover
So you will have to lift that cover for pulling out pin and the shaft
That means to losse the nuts on the studs fixing the head ?
As far as i see yes
Usually i would say if you do it, just do it right.
But...
Maybe some kind of seal swell will help.
If you will not put such stuff into your engine it might be possible to put a little amount of this stuff on the outside of the decomp shaft in the head.
Hoping it will crawl to the inside and reach the o-ring
Maybe it's worth a try before dismountig nearly the complete engine
ciao Joachim