Re: Mercury V6 Poppet valve Replacement
It is simple to take off the lower cowling, just remove the screws and make sure you can lift the hoses out of the rubber thing where they go through the front of the cowling, nothing to disconnect.
The parts you describe are about it, there is a stainless washer and spring. I would buy every thing except the cover and put in all new. Be careful not to let the thimble think fall into the block, it fits over the hole. Thimble is not the proper name but you get they idea. That works as a seat for the poppet, so put in a new one.
The poppet just lets excess water dump into the exhaust at about 3000 rpm. I would install a water pressure gauge if it were mine, I think they are the most useful thing you can have on an outboard engine.