That's a great find! I think it is just the most recent batch of four or five that are without English subtitles - all the others that I've checked do, but many get hidden behind the YouTube pop-up adverts that appear at the bottom of the screen. Luckily these ads can be closed down when they appear. Hopefully this list will be helpful for future reference (I know I'll be using it to quickly get to the interesting films!) I haven't really organised them much, just into comedies and fairy tales and groupings of a number of films by a particular director:
Comedies:
Jewish Luck (Alexis Granowsky, 1925)
Kuban Cossacks (Ivan Pyryev, 1949)
The Diamond Arm (Leonid Gaidai, 1969)
Gentlemen of Fortune (Aleksandr Seryj, 1971)
Mimino, an early comedy from the director of Kin-Dza-Dza. (Georgi Daneliya, 1977)
Kin-Dza-Dza! Part 1 and
Part 2 (Georgi Daneliya, 1986)
The Chinese Tea-Set (Vitali Moskalenko, 2002)
Fairy tales:
The New Gulliver (Aleksandr Ptushko and A. Vanichkin, 1935)
Sadko (Aleksandr Ptushko, 1953) - a version of Sinbad, whose US dubbed release was later used in an episode of MST3K.
Ilya Muromets (The Epic Hero and the Beast) (Aleksandr Ptushko, 1958)
A Tale of Lost Times (Aleksandr Ptushko, 1964)
The Tale of Tsar Saltan (Aleksandr Ptushko, 1967)
Viy (Georgi Kropachyov and Konstantin Yershov, 1967) - the most famous Russian horror film.
General groupings:
October (Sergei Eisenstein and Grigori Aleksandrov, 1928)
Circus (Grigori Aleksandrov, 1932)
Jolly Fellows (Grigori Aleksandrov, 1934) - Charlie Chaplin, Harold Lloyd and Buster Keaton are....
not appearing in this film!
Volga-Volga (Grigori Aleksandrov, 1938)
The Enchanted Way (The Shining Path) (Grigori Aleksandrov, 1940) - this one is not listed on imbd.
Ballad of a Hussar (Eldar Ryazanov, 1963)
The Irony of Fate, or Enjoy Your Bath! (Eldar Ryazanov, 1975). In two parts.
A Railway Station For Two (Eldar Ryazanov, 1983), which is in two parts
A Cruel Romance (Eldar Ryazanov, 1984)
Forgotten Tune of the Flute (Eldar Ryazanov, 1988)
We Are Jazzmen (aka Jazzmen on imdb) (Karen Shakhnazarov, 1984)
The Messenger as described in the subtitles but known as
Courier on imbd (Karen Shakhnazarov, 1987).
Zero Town (Karen Shaknazarov, 1990)
Full Moon (Karen Shaknazarov, 1998)
Poisons, or the World History of Poisoning (Karen Shaknazarov, 2001)
The Rider Named Death (Karen Shaknazarov, 2004) - out from Kino in the US.
The Vanished Empire (Karen Shaknazarov, 2008), also out from Kino
The Fortune (Happiness) (Aleksandr Medvedkin, 1934)
The Russian Question (Mikhail Romm, 1948)
9 Days of One Year (Mikhail Romm, 1962)
The Cranes Are Flying (Mikhail Kalatozov, 1957), which begins with an ominous untranslated thirty second passage before the subtitles begin with the Mosfilm logo. Presumably the untranslated bit is informing audiences of its Palme D'or win - either way this small section does not appear on the Criterion edition of the film, which starts with the Mosfilm logo.
Ballad of a Soldier (Grigori Chukhrai, 1959)
July Rain (Marlen Khutsiyev, 1967), which looks kind of Nouvelle Vague inspired
Two Soldiers Were Serving (Yevgeni Karelov, 1967)
The White Sun of the Desert (Vladimir Motyl, 1970)
Who, If Not Us (Valeri Priyomykhov, 1999)
Mirror (Andrei Tarkovsky, 1974)
Here's a particularly interesting one:
The Beginning of an Age Unfathomable (Larisa Shepitko and Andrey Smirnov, 1967), a film Shepitko made following Wings.
Agony (Elem Klimov, 1981). In two parts.