I want to be clear on what the problem is. You said "a piece of the cylinder block chipped off" but you are looking for a cylinder head. The block and head should be two separate pieces. Where exactly did the piece of metal break off.

I doubt that you will find just a used lawn mower head for sale. It's possible I suppose but unlikely that someone will part out a mower to that degree. You will have a better chance of finding a complete mower. However, have you priced a new head? If it were me I would do enough work to get the mower running. A little smoke is no big deal. If you feel idling is fouling the plugs then shut the engine off.

Unless you have the skills and tools to hone the cylinder and remove any ridge you should leave that work to a professional.

From what you have written so far--let me make 2 suggestions:
1: Take it to a person who is a real mechanic!
2: Set it at the curb, and somebody will take it away and scrap it for you, although you won't get any money for it.

I'd say, to keep the grass from getting so high that you won't be able to see the street or mail-box, go buy one of the good, dependable mowers made here in the USA, and keep the foreign junk out and away!
I scrap any Honda mower engines i get here. I don't save the cylinder heads, nor any other parts! Gone, forgotten, good riddance!
And, if you are not mechanically experienced, let the real mechanics do the work. It'll save ya money in the long run!

Thanks Roadbike,
It broke where the spark plug screws in. I will do a compression test next to see if leakage is causing the mower not to start. I was just thinking if I replace the head I could go ahead and put new Std piston rings on too. I could just tear down the mower a little further. This smoking is a common problem I have read on other forums. I have so many tools I do not use much like a compression tester, ring compressor, and cylinder hone. I work on my car and bike. I read manuals and then work on stuff. I am good at disassemble and reassemble.
So far I have torn down and cleaned the carburetor, replaced the throttle cable, topped up the transmission fluid on this mower, and fixed the recoil starter on my Honda HR214. I broke the recoil starter on this model (HR215HXA) and can not figure out how to take it apart. It has a center pin that has to be bent or something to remove the other parts. I may have to buy the whole assembly for this. I just do not like the though of a chipped head on my mower and since I have another one that works, why not just fix this one?
Please let me know If I am on the right track. A new head is $63.00, a ring set $12.00, and the recoil starter $20.00, I could have a almost new old mower when I am done? I was wondering if re-honing or boring or whatever would be necessary for my mower in my case? What needs to be done if I tear it down that far. In other words, how do I get the mower in the best condition before I reassemble everything for what I am talking about having done.
If I order a new head, do I just re-seat the valves with lapping compound or do I have to go to a machine shop? If I go this route I might as well let them hone the thing. If I go that far, maybe I should consider getting an over-sized piston and rings which would require a re-bore of the cylinder.
I am just listing some options as I understand them. My experience is that if its not done right, you have to take it apart all over again and re do it all.
Rusty, I like to tinker and take my time. If it works great if not, its scrap anyway. I just want to keep trying and learning. You are right, I am not a real mechanic, but every time a 'real' mechanic works on something for me, I later discover something they broke or messed up, Thanks.

They make kits where you can fix the spark plug thread.
This happens when the spark plug is removed when the engine is hot or over torqued.
I suggest looking for the kit they cost about $15.

I don't understand your description of what broke, please be specific if you want help.

If the metal actually broke off near the spark plug hole that would be highly unusual but the head that can't be repaired easily. I still don't know what broke off - a fin maybe? If there isn't a hole or crack down into the head then you may be ok.

If on the other hand the threads simply stripped out then yes as rosemallow said there are kits available. Several brand names are available but helicoil comes to mind right now.

If the head is $65.00 I would just get a new one and not fiddle trying to find a junker.

Please don't take this the wrong way, but your questions lead me to believe that you don't have the experience needed to undertake this job. In short you could end up causing more damage that a mechanic would ultimately have to fix and charge you for. If you want to get this mower running again please take it to a good mechanic for an estimate. Otherwise just buy a new mower for $400 to $500.

Thanks again those who responded,
Roadbike, The spark plug hole that goes into cylinder block goes in at an angle to the cylinder head. It is not flush with the head. Part of the hole protrudes out from the head. This is what chipped off. It was only a small piece, but it contained some of the thread from the spark plug hole. Sorry I am not an expert and this is a 15-20 year old mower, so what I am doing is trying to learn something as I attempt to repair it and use the tools that I have. I am not going to spend much money. You see I have an older Honda HR 214 that setup for at least 10 years, and I got it running last year as a backup mower.
I think just replacing the head will work. I could use the valve parts from the old head and simply put them in the new one. A complete head is $157.00, what I was wondering is do I have to get a cutting tool to seat the old valves to the new head or is that done for you and all I need to do is re-seat the valves with lapping compound? Since the thing was smoking, I simply thought why not put on new rings. I was wondering what one does when they put on new rings? that is why I asked the re-honing question.
Thanks for your insight and yeah I may not have the skills, but I would like to try before I trash the mower.

Thank you sir and rosemallow

Oh, yes, you will learn something, all right!
And, if you live anywhere near Pittsburgh, Pa. stop in and i'll give you several of those Honda lawn mowers--free! I don't need that junk in my yard. One needs a flywheel key, the other one might run without much more than a tune up! Let me know--i'll send contact info and an address!

Thanks again Rusty,
I live in the Northwest Corner of AL, too bad cause I could use your help. Do you know how I could find a yard in AL or TN that may have some old mowers laying around or how I could search for one on the net?

I have great running Honda HR215 self propelled mower the tranny locked in gear cant be fixed hate to junk it could you use any parts?? Rick in ncpa
backman56@verizion.net
let me know what you need.

I really wonder what happpened in Rusty's experiences for the Hondas to leave such a bitter taste in his mouth when everyone else raves about how great they are. If he is in sales, then maybe the issue is people buying Hondas (my old one says made in USA) or what?

Because Rusty is a WWII vet?

My reason for not liking Hondas: They are too complicated for the average home-owner/business world worker/ cook/ housewife/ inexperienced would-be mechanic/ or any other type of those genre. Hokey mought be the word for them! A pox wished on us by the japs, in retaliation for the drubbing we gave them!
I got my experience with mechanical stuff by going out and getting hired at the local Ford Dealer in our town. Fresh out of Army with a wooden foot! Went to work every day except Sunday! Kept my eyes open, my mouth shut, and washed a lot of parts, until i learned how to fix the engines, and related parts. I didn't learn anything by taking the sledge-hammer routine, nor by changing spark plugs with a 4-foot Crescent wrench! (Point of info: A Crescent wrench is not called that because it is shaped like the 1/4 moon!) I also learned the saying:"Lefty-loosey/ Righty-tighty", which all would-be mechanics should learn as soon as they pick up their first wrench!
I also learned that a real mechanic, or even a "Wanna-be", must have more tools in his tool-box, than 2 bent screw-drivers, a BFH, a Crescent wrench or two, and assorted"Farmers" bolts and nuts! (Thats the round head, slotted type, that ya use a crescent wrench on one end, and a flat screw-driver on the other.) My Grampaw was a farmer, and he had buckets of them--assorted. RJ

Answer me this: Where, oh where, did we go wrong in the portioning out of BRAINS? Was it caused by the original yuppies, and their resulting off-spring inheriting their mental processes?
Or: Was it caused by the fact that some folks couldn't pour water out of their boots---even if the directions were printed on the HEEL?!
I doubt that the original poster will take our advice. He is either rattling our chains, spoofing us, or is honestly dumb about mechanical processes! At which point--the BFH is surely the optimal tool for him to have in his tool collection! When all else fails---use the BFH!

Some are attributing todays generation's lack of brain power to all the recent artificial additives in processed food. TherecCould be some truth to that I guess, but in the fast-paced society we live in I feel that a lot of people fail to just stop-and-think before they react or perform in a given situation. Thanks for answering your disdain for Honda's. I was just cuious that is all. From what I have seen of them (very little) they use some overkill for basic lawnmower functions that may lead to their difficulties in repair.

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.