I think it's a shame so many people are making fun of this poor juliez. Not everyone has the good fortune to learn engines and stuff. At least give them credit for mowing their own grass. That being said, has it occurred to anyone that the spark plug might be covered by a plastic cowling? I was at Home Depot today to get parts for my powerwasher, which also uses the Honda GCV160. And I happened to notice in passing that the mowers using that engine do, in fact, have a big plastic cowling around the engine. For an inexperienced person who does not understand the basics of engines, it would be easy to not be able to find where the spark plug is. Out of sight, out of mine! My advice, if you're still looking for it, is to unscrew the plastic covering on the engine. At the front, you will see a little white cylinder sticking out. The spark plug wire pops on top of that. As others have said, you may need to change the spark plug. That is as simple as getting a spark plug wrench, which is a little $5 device that looks like a penny roller that you stick on top of the spark plug and turn to remove it. Remember, righty-tightie, lefty-loosie.

I'm sorry your salty rusty. IMO its a huge waste of time being bitter and in this application, loggers nothing helpful or insightful at all to help the OP with their issue. If you are only comfortable with the antiquated flathead design of some companies lawn equip then I myself would wonder if you have trouble pouring water from your own boots, directions included or not. To say that OHV design is finniky or hokey is quite amusing as its about as that design is almost as old as the hills aswell and is quite straightforward and offers myriad benefits in every aspect compared to other designs. I'm a 30y old car salesman and have been doing it for 10y. Even though I often work 50-60h a week, I have enjoyed replacing transmissions, engines, installing super/turbo charger systems on many different typed of real cars (perhaps to your delight/dismay, mainly Fords) and also just about every other electrical/mechanical process imaginable. So to make inaccurate, broad but mostly ignorant comments about younger generations just shows the exact same traits in yourself that you so loath in mine. OP, from what I gather with the info you have provided it sounds line you broke a chunk of the threaded plug material from the mower. IMO it would be best to either purchase a whole new engine (perhaps craigslist), or find a local reputable machincr shop and see if they can repair the problem. Other than that maybe you could get a gsv160 (newer Honda motor for lawn equipment) and put it on your mower. From the little searching I did on your motor, they are not readily available and when found are quite expensive. The gsv160 can be had brand new (not rebuilt/furbished) for ~$200.

Why not go back to Menards? I saw one of these on an old eBay listing and the seller said he bought it last year. One would think that Menards was likely his source for it as it's not unusual for such items to be private branded items. I Googled it to see if something else came up but no luck.

The leak is still the valve cover gasket, or else it's actually at the bottom of the spark plug tube in the head. Simply replace the gasket, and the tube seals, clean the oil out, replace the plug AND the wire and don't worry about it. If it gets oil in it again, it will eventually cause a driveability issue and you will need to install new tubes in the head at that time. (That of course "assumes" the spark plug tubes are serviceable parts) As far as the milky substance goes, your jumpng the gun on the diagnosis. Do you really have any other symptoms of a head gasket or other kind of internal coolant leak? Some condensation from exhaust blow by gasses is normal. Generally the engine oil has enough additives in it to hold this moisture in suspension, until it is boiled off and then picked up by the PCV system, and then removed from the engine.