I had the same problem and followed all the advice. changed spark plug, emptied gas tank (twice) and filled with fresh fuel, took carburetor apart and poked holes with wire, put Seafoam in the gas and sprayed the the carburetor intake. Nothing worked; it would start with starter fluid but quickly sputter out. As another comment said, these walk mowers don't have fuel filters and I was told by Sears I would have to replace the gas tank. Since this was the only tip left and wasn't sure I had the skills I am officially giving up and taking it to the mower repair shop down the street. It's only a year old. The only other thing I can think of is that the mechanism that triggers the fuel release isn't working properly although it appears to be. but somehow fuel is not getting to the engine from the tank I think. If the shop can fix it, I'll comment back what it was.

Must of been lucky. Bought an MTD at Ace hardware (Ace Special Edition) with a 42" cut and 16hp Tecumseh. Aside from the normal problems of your MTD of that era IE having the grille mounts break off after a few years) it's been great, and it was only replaced as it was really starting to not work well on hills, and in the last year has been a case of "What's going to break next when I mow?". A key to remember is any NEW tractor in that range is going to be light duty. If you have more an acre to mow with it, a newer, higher end, used model is a probably a better option. You'll get a lot of life out of one though if you keep it well maintained. Take care of it and there is no reason why you should not get a good, usable life of about 10-12 years. one other thing to keep in mind; the chief complaints of many people on a mower it seems is the motor. That is the most important part of a mower besides the transmission on a Hydro equipped tractor. The engine is going to what will go wrong 9 time out of 10 on a mower, and is often going to be to blame for issues with cutting (due to lack of power) and reliability.

I have a very similar problem with a Briggs & Stratton 17 HP engine. I have put in a new carb overhaul kit. (The float was gunked up pretty bad, but now looks new, checked for leak or holes in it, found no indication that float is damaged.) Put carb back on engine. Engine runs, but poorly. It sounds likes it chugging, noticing black smoke out of exhaust especially at Idle. One thing I didn't notice in all the above posts. Is the adjustment needle on the carb an IDLE adjustment needle or a main needle? What is the initial setting? The engine does have spark. Although one spark plug shows more of an orange spark rather than blue. Both plugs were damp from unburned fuel when I removed them. (They are old plugs.) Engine running: It'll sit and run. I can drive the tractor. However when I slowly engage the mower blades (blades are new, bearings are good, belt is new) the engine dies, unless I quickly disengage the blades and apply full choke. Heading out to store to get new spark plugs this morning. I've already poured quite a bit of money in this beast. I may be the one who has a rolling ball of fire!

That might be true, on the vibration. This engine is 24 years old lol; it's still running strong when I can keep everything firmly connected. I HAVE had issues with the engine mount bolts coming loose and have to tighten them up regularly. Discovered when we inherited the tractor from hubby's grandma that the engine was being held to the frame with only three of four bolts, and those just regular bolts, not the OEM engine bolts, if it makes any difference. Got four OEM B&S engine bolts on eBay, and the lock washer that was supposed to go on one of them, but that one somehow came loose and fell out someplace. So back to a regular bolt in that hole. But I periodically tighten those bolts because they do seem to work loose; there is definitely some vibration going on but don't know if it's related to the PTO or not. No problems engaging or disengaging; no unusual vibration. So probably a good case for the carb bolts working loose; once they loosened (before I discovered the problem with them and the engine mount bolts) maybe they started wearing on the bolt hole threads??? Anyway, back to current problem. The bottom screw on the carb mount still can be tightened I think, but the muffler shield on top of the muffler directly below the carb is in the way making it REALLY difficult to access or pull the bolt; you can barely work a screwdriver in there to turn it and you have to bend the back edge of the shield down to do that. I think I need to use Locktite on both bolts though. I tried re-doing the Locktite on the top bolt and tightening the bottom one, and it held for all of about 5-10 minutes of running. After that I ended up bungee-cording the air cleaner to the engine to hold it against the engine block just to finish mowing, but by the time I was done both bolts were loose again. The carb mounts to the left side of the engine, btw. I can link you to a diagram if you like. (see below) I used the same tube of locktite I had from three years ago (still pretty liquid) but maybe it was no good? It was the removable type of Locktite and I am wondering if I should try something with a little more hold? Would JB Weld be better? I noticed it did grip the bolt in the hole better once it began to set but was afraid to tighten it down too much; just turned it till it felt like it was catching a bit and then let it set. Otherwise the bolt would just spin in the hole. I have gotten some more OEM bolts to try new ones but they are shorter than the bolt I used last; last time I just used an ordinary bolt that was a little longer than the original, and it did the trick, but this time I used the same longer bolt and it let go, after applying Locktite, tightening as best I could, and letting it cure 24 hrs before running. Should I replace the carb mount gasket again too? Seems to be ok but I haven't pulled it; I replaced it last go-around. The mower starts and runs just fine if I can just keep the darn carb on the engine! Here is the link showing the carb and air cleaner assembly for my B&S engine, no. 280707-0411-02. If you look at the carb bottom left, you can see the attachment point (intake??) you can also see the bracket I was referring to (no. 662 in the chart). Just a strip of metal that attaches to the little box with the choke linkage on it. Doesn't really support the carb-to-engine connection; the whole unit including aircleaner and bracket moves, I think. It's screwed down pretty tightly regardless. Carb and aircleaner assembly B & S 280707-0411-02 Thanks for any suggestions or advice!