A recent thread about thermostats got me thinking. I never did locate the thermostat on my 77-500/50. The sealock manual mentions it but only in a very general sense. I have looked for it but never did pin it down. I think I know where it would be but it apears that this model, 4cyl is not equiped with one. None of the parts suppliers show one for this engine either. Can anyone tell me "yes" its there or "no" it isnt???