It appears then that Paul's engine is an OHV13.5 in the manual. However I can't find any specific reference that model in the decompressor or camshaft sections. Hence the basic decompressor information, as I read it, is the ordinary MCR (Mechanical Compression Release) information, which implies that it follows Figure 38, which shows a thrust washer between the timing gear and crankcase cover. Paul's engine does not have the washer, and the parts list does not show one. Either I'm missing something, or Tecumseh missed something.