I am having the heat exchanger cleaned and replacing the coolant in the system. The radiator cap is showing rust signs. I want to replace it but I can't find any pressure recommendation marking on it. Also, I am unable to locate any thermostat. The manual does not mention the cap or a thermostat. Any suggestions on the cap or if there is a thermostat will be appreciated. Thanks.
It is a Yanmar engine. I may look like a thermostat in the usual place on top,, it is not. Your thermostat is located on the lower back end of the water cooled exhaust manifold assembly. Thermostat part number GM47556 alternate part number 254920 Gasket part number 229963 Kohler cap part number 229980 I think it's a 13lb cap. I usually install 11lb caps. Use the same coolant as your mains. Check over your belts and hoses also.
Yes it is a Yanmar engine. Thank you for the info. I will order the parts this afternoon. I will be using the same coolant as in the mains. I did replace the belts last season and the 5/8ths hose is being replaced. all other hoses look and feel good. Thanks again.