DO I need to order any extra o-rings or gaskets to replace the thermostat on a 617?
 

I bought a thermostat off Phil and I didn't get any gaskets. I bought the thermostat housing gasket but that is for the place where the whole assembly bolts to the block (or head for that matter). But what do I do about the place where the thermostat cover meets the housing? SHouldn't there be some sort of gasket there?
Thanks
David

o-ring required for thermostat replacement
 

You will need a rubber O-ring. The thermostat is inserted in the ring and then you put the whole thing in the thermostat housing. The ring is shaped to fit in place. Be sure to orient the thermostat so that the bleed hole is on top. If the thermostat is pretty old you may have some difficulty removing the old o-ring as it will be baked in place.

So there isn't a gasket and it should just be attached dry? I am speaking about the cover that's held on by 3 10mm bolts.
Thanks
David

There's only the rubber one. It makes the seal. If it's pliable and intack, just clean it and reuse it. The aluminum housing can get coroded and lmay need a cleaning too.