Look on the crankshaft and cam gears for little marks stamped into each part. When installing the crank and cam, turn both gears by themselves, until you get the marks lined up, one mark between two teeth. This will set the timing. Remember the cam gear turns twice to one turn of the crankshaft. This for a four cycle engine. I offer this, in good faith, but there might be some engines where the marks are different, but this is usually the norm. Oriental engines may have slanted marks, so---

I am really tired today running between all the big box stores. At the end, I didn't option the lawn boy because I really can't justify the extra cost vs sears promo today. Plus, a technician at Rona's service center gave me a friendly warning about the Tecumseh engine, the supply of the parts might be good for next 2-3 years but can't promise anything at long run. I still have a thought that a good mower should last me 10 years ironed in my head... However, I really like the design of the lawn boy 10684, everything seems very well design and build quality is better than others. If it's around $350CND range and none self-propelled model, I would pull the trigger, no question ask. I went back to Sears and ordered the Craftsman 36933 model (3-in-1 with bag, side discharge, mulching), which has B&S 850 platinum engine (8.5 ft/lb torque), no choke and no primer needed. The price is just what I am aiming for, 289.99+taxes. The engine seems pretty well build but the rest of the parts are very standard, a regular every week lawn mower...

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.

i removed about 2 oz of oil to make sure it wasn't that stupid. dad didn't seem concerned about that saying it was an insignificant amount. difficult to get an accurate read on the oil level due to the stupid plastic dipstick design but it seems at the correct level. i probably should stick a screwdriver in it to get an accurate read, but like i said, it isn't over-filled oil. i know the symptoms of too much oil -- heavy black smoke and very erratic performance. this is a slight black smoke, excessive fuel consumption (rich burn, burning fuel 4 times faster than it should), slight erratic performance, and degraded rpm. new spark plug was installed and gapped to 0.76mm (factory gap was actually correct). removal of air filter was tested. it is a new air filter replaced 2-3 weeks ago and frequently dusted -- i also typically use a very porous 2ndary filter (similiar to the filling of a comforter) as well to keep larger stuff off the air filter. it isn't those things. i've used new gas from two different sources. i've thoroughly cleaned and checked the carb (needle valve was perfectly clean like brand new and functioning correctly with the floater, the bulb was perfectly clean like brand new except of course with clean gas in it), everything looks good, and really, there isn't much that could go wrong with the carb with everyday use, unless i was burning sand and sludge. i also examined and cleaned the breather and it looked in good condition. the breather was clean except for the expected oil and functioning perfectly. i'm really just asking for advice on what to expect for tearing down the engine, if there is anything special that i need to know. my dad thinks it ran hot with the choke getting stuck and not releasing fully. it is likely internal to the engine. hopefully, it is just a worn belt considering 500 hours (5-10 years of residential use) is about the life of a residential mower engine, but i may have to replace rings and hone the cylinders if it was because of the automatic choke release being used and not releasing even though the lever was fully released due to dirt build-up around the linkage for it. everything else was just fyi to give my review and experience with the craftsman mower and honda engine.