  Fifty-one objects in the 5_{-1}-4_0E methanol line at 84.5 GHz were detected
during a survey of Class I maser sources. Narrow maser features were found in
17 of these. Broad quasi-thermal lines were detected towards other sources. One
of the objects with narrow features, the young bipolar outflow L 1157 was also
observed in the 8_0-7_1A+ line at 95.2 GHz; a narrow line was detected at this
frequency. Analysis showed that the broad lines are usually inverted. The
quasi-thermal profiles imply that the line opacities are not larger than
several units. These results confirm the plausibility of models in which
compact Class I masers appear in extended sources as a result of an appropriate
velocity field.
  Measurements of linear polarization at 84.5 GHz in 13 sources were made. No
polarization was found except a tentative detection of a weak polarization in M
8E.
