Thats what I've seen used. On one build I saw a bit too much of it squish thru and restrict the oil o ring gallery.I am in the process of doing the topend and in the haynes manuel it saying to use a liquid gasket sealer on the base gasket any suggestion I was thinking of using yamabond 4 or threebond 1211
This actually doesn't look as bad as mine was. I'm in the process of tearing down my '01 750ss engine to address several oil leaks at the cyl bases, head-to-cyl surface, case halves,valve adjustment, etc. Sometime before I owned it, the vertical cyl was re-sealed at the base with a sandwich of lots of goop, metal gasket, lots more goop, metal gasket, then even more goop! The oil passageway was so clogged that a little cone of cured sealant was formed with just a pinhole getting by. So, I'm pretty glad I decided to do the whole teardown when I did. The other thing I found was the o-ring between the horizontal head & cyl was crushed, torn & deformed leading to the really big oil leak. The question I have is should I not use more o-rings and use a liquid gasket product, and if so what is the best one?Thats what I've seen used. On one build I saw a bit too much of it squish thru and restrict the oil o ring gallery.
Since some of the base gaskets use no sealant, my next build I'm going to try the Permatex "copper" spray sealant. Very thin, and seals irregularities in mating surfaces. High temp/High pressure.
On my ST2, I put it together with NO base gaskets in order to get 1mm of squish (one of my LeMans is also done this way, my friend's Guzzi 750S that I just restored, and I ALWAYS did aircooled VWs with no base gaskets), so I HAD to use 3-bond (on the VWs I used Permatex brown stuff, but this was 30+ years ago).I have never used a sealant of any kind on cylinder base gaskets. These soft aluminum or copper gaskets are designed to go on dry - I disagree with the Haynes manual. In almost 30 years of rebuilding VW Beetle, Harley Sportster and Shovel head, and Porsche 911 engines, I have never had one leak.
Remember, deck height is set with the base gaskets. Any additional material in that joint will increase deck height. Fortunately, the head stud torque value is high enough to squish it all back out anyway. Which leads to the problem shown in the photo above...
Anyway, it's not necessary, and no good can come of it. Best to leave them dry.