Well, I can't loan you any money, and I can only speculate about the guy selling yard equipment, but it occurred to me while working on a lawn mower with my 12 year old step son, Austin, that I may be able to help you out. Someone in my neighborhood put a 3.5 hp Craftsman lawnmower with a Tecumseh engine out for trash. It had no air filter and the muffler was rusted out, barely holding on by one bolt. The deck was rust and dent free, it was a mulcher/bagger sans bag. The wheels were in pretty good shape although a cotter pin had been replaced with a bent nail at some point in time.

I just wanted to give Austin a little more knowledge about gasoline engines without the time and expense of rebuilding one. Last year, he wanted to buy a lawn tractor someone was selling for $5, we already had one in the garage, I knew his mom wouldn't stand for two. I figured, if we can make this lawn mower run, great, if we can't, we can disassemble it and he can see all that goes into turning combustible noxious fumes into useable power.

So we started off in the usual manner, pull the cord, it turns over, but doesn't run. Take the spark plug out, he holds it (using electrically insulated pliers) against a ground, I yank the cord. There's spark, so the simple magneto works. Put the plug back in, spray "ether" (starting fluid) down the carburetor throat, yank the cord, it runs for about 3/4th of a second. Try again, runs for about three quarters of a second.

So, we've confirmed that we have compression and "fire" (spark) we're obviously not getting fuel.

I add more gas to the tank there was some in there to begin with, but it may be contaminated, it may not be enough to reach the line, it could be stale. Repeat the starting fluid, yank, run, stall process several times, while messing with the throttle each time. It runs, very poorly. I pinch off the fuel line with vice grips, open the carburetor bowl, there's a layer of green slime at the bottom. Dump it out, clean it out, reinstall it. Spray, yank, it runs, very poorly.

I'm thinking that perhaps the lacking air cleaner is making it run very lean. So we  fabricate one with some scrap metal, pipe and air conditioner foam laying around the garage. Install it, spray it with starting fluid, yank the cord. It runs for about 10-15 seconds and then shuts off. I yank the cord without starting fluid, it runs for about 10-15 seconds and shuts off. Clearly we've made an improvement, but it's still being starved for fuel.

We drain the gas tank, remove the carburetor, examine the fuel line. It's old, but it's in pretty good shape. I would normally replace it, but Austin really wanted to see if we could make it run on the cheap. We take the bowl off the carburetor again, Looking very closely at every nook and cranny, There's a pin hole on the retaining bolt that also acts as a line from the bowl. It's fairly clogged. Using a piece of wire from my welder's brush (it was the smallest diameter wire I had) we clean out the hole, which was actually twice the size clean as it was gummed up. For good measure, we clean every other surface of the simple carburetor, which is basically a bowl, float and venturi. We reassemble all. We've been messing with this for an hour, it's dark. Unfortunately, we forgot to connect the butterfly back to the throttle linkage. We have nothing, it won't even run on ether. We put it in the garage and call it a night.

A few days later, I had time to wrangle with it again, I knew that we forgot a piece of throttle linkage, so I quickly tear it open, reconnect the linkage, snug down the bolts. I yank the cord and presto! It runs and I haven't spent a red cent on it. It misses every now and again at low idle I can't hear or feel any miss at high throttle.

Did I mention that the muffler was almost non-existent? I forgot, I couldn't hear myself think.

The old muffler was held on by two bolts, one is missing all but the stub that's broken off, the other broke when I tried to remove it. The good news, the exhaust port is threaded and can except a screw in muffler. These cost from $5 to $15 depending on where you get them. When I was at Lowes for something completely unrelated, I thought I'd stop and look for one, this particular engine needs a 1/2" threaded muffler. I know this because I measured with my trusty finger. Lowes does not appear to carry any mufflers, but they have every air filter made for just about any small engine. I didn't want to try the local ACE Hardware because the owners tend to charge an arm and a leg. Other ACE stores are more reasonable, however. You may want to try them if you need a small engine muffler. So I walked down to the plumbing section, got a 1/2" X 1 1/2" piece of threaded black pipe for $0.68, after taxes, $0.75, which I welded to a muffler I fabricated using scrap sheet metal and what was salvageable of the lawnmower's original muffler. Total time spent was around 2 hours, all though it probably would have been much less if I didn't take the time to explain what everything was and how it worked to Austin. Or if we had started a little sooner, we wouldn't have been putting it back together in the dark, we could have put the throttle linkage together right the first time.

I'm not including any photos with this article, every brand and size will be slightly different. Most engines will be Tecumseh or Briggs & Stratton. You'll need creativity more than any other tool to have the success I did. Any one who tries this is more than welcome to send a photo and your particular story, or just post your story in the comments section.

And there you have it, the $0.75 lawn mower at Mechlogs School of Small Engine repair. The blades have been sharpened, it cuts great. It's for sale, $35, stop by my house any time after dinner...