The engine itself was used by OMC, Volvo and a Mercruiser along with many other manufacturers for things like water pumps and fork lifts. So there is no shortage of parts for them.. where your going to have issue is with anything that is Yamaha specific. You’ll need to get an exhaust riser to fit the exhaust on your boat. It shouldn’t be impossible but you’ll have to figure out what fits.
Sorry - I was reading that on a little screen without my reading spectacles and thought you were referring to the engine circulating pump.
If the age of the impeller is unknown, replacement is wise.
As far as the thermostat goes, search for these:
Mercruiser 59078
Mercruiser 18-3650
Mercruiser 18-3550
Thanks for the updated info. I will pull the outdrive and check the impeller. I found a kit that was OMC cobra that will work I’m told. My AZ local store is ordering me the thermostat so I’m just waiting on that & gaskets now. The thermostat gasket is something I’ve not been able to find even off eBay where I found the thermostat housing gasket.
