Thermal, magnetic, neutron and muSR measurements all point towards a gapless or almost gapless spin liquid ground state for the triangular lattice spin system of S=1/2 Mo3 clusters in the compound Li2ZnMo3O8. It is suggested that 2/3 of the spins form a honeycomb valence bond solid (VBS) below 100 K with a finite spin gap, leaving the remaining 1/3 of the spins to form a gapless triangular lattice spin liquid with an enlarged lattice constant and weakened coupling via the VBS sites. New muon measurements will explore the boundary between spin liquid and magnetic phases and will be used to extract critical parameters to test against existing models. A search will also be made for the signature of 2D diffusive motion of spin excitations, a feature that was seen in several other triangular lattice spin liquids previously studied with muons, giving further information about the criticality.