  We present moderate (1'') and high resolution (0.2'') observations of the
CO(2-1) emission at 43 GHz, and radio continuum emission at 1.47 GHz, from the
z=4.7 QSO BRI 1202-0725 and the z=4.4 QSO BRI 1335--0417 using the Very Large
Array. The moderate resolution observations show that in both cases the CO
emission is spatially resolved into two components separated by 1'' for
1335-0417 and 4'' for 1202-0725. The high resolution observations show that
each component has sub-structure on scales of 0.2'' to 0.5'', with intrinsic
brightness temperatures > 20K. The CO ladder from (2-1) up to (7-6) suggests a
high kinetic temperature for the gas (70 K), and a high column density (10^{24}
cm^{-2}). In both sources the continuum-to-line ratio: L_{FIR}/L'_{CO(1-0)} =
335. All these characteristics (brightness temperature, excitation temperature,
column density, and continuum-to-line ratio) are comparable to conditions found
in low redshift, ultra-luminous nuclear starburst galaxies. We find that the CO
emitting regions in 1202-0725 and 1335-0417 must be close to face-on in order
to avoid having the gas mass exceed the gravitational mass, implying perhaps
unreasonably large rotational velocities. While this problem is mitigated by
lowering the CO luminosity-to-H_2 mass conversion factor (X), the required X
values become comparable to, or lower than, the minimum values dictated by
optically thin CO emission. We considered the possibility of magnification by
gravitational lensing in order to reduce the molecular gas masses.
