Folks, I have an older Craftsman lawn mower that I can't get to start. I do get a good spark, so I'm assuming that it means a clogged carburetor. Is there anything that I can pour into the tank and allow to sit there that might help dissolve any old varnish? Thanks in advance for your suggestions!
remove sparkplug, put in a little fresg gas, reinstall plug, and try starting.
did you leave old gas in it?
More than likely varnish has formed over the fuel pickup screen. Remove the carb and blow everything out with aerosol carb cleaner.
You could get an electric, learn to do the "cord dance," and never worry about starting the mower again. With an electric, you just turn it on. If it doesn't start, buy a new one, they're only $150 or so. End of problem.
I can't even see my lawn. It's snowing. You think YOU have problems?
You could try draining any old gas. Re-fill with fresh gas. Remove the air cleaner and squirt 1/4 tsp or so of gas into the carb. Does it fire up now? If so, but it then dies, repeat the priming with gas a few time. It may clear itself out, and run.
Bob
I think he has one of those new models that blow away the snow and cut the grass at the same time. They're used by people who are running late.
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Doesn't anyone suggest small parts cleaner anymore, or whatever it is called. It comes in a can a little bigger than a can of Giardelli cocoa, or a pound of whipped butter, but with the walls vertical, and one is supposed to disassemble the whole carb and soak every part that does not contain plastic in it. They usually have a basket inside the can so you can pull out the basket and let most of the solvent drain off, then wash the parts in water while still in the basket. A lot stronger than spray or liquid gumout, at least it was 40 years ago. I bought another can about 15 years ago, at an autoparts store, by a major maker, like gumout, but I don't know if it was as strong as the prior stuff.
Or is it that there are too many rubber or plastic parts firmly affixed to the metal ones?
Do you guys know about this stuff, and if so, do you use it?
At any rate, if this or the other suggestions don't work, there are one or two parts that can be replaced where the clog is. I was in a hurry and the repair guy talked me into 4 or 5, for maybe 20 or 25 dollars, but if money is tight, you could do them one at a time. B&S engines have exploded views, part numbers, and a list of dealers on line, although Ithink the place I went to was not on their list, even though it had everything. It was closer to my home.
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and always replace the spark plug.
Well, folks, an update on the lawnmower. It is actually a Craftsman edger, the one with the blade that has 3 edges (triangular shaped blade). I cleaned it up, sandblasted the spark plug(and determined that it is getting good fire)re-gapped it, then took off the gas tank, took the carburetor off, sprayed it inside and out with carburetor cleaner, put it back together, and NOTHING! I put on a spark detector gizmo that lights up when I pull the cord, so I'm sure it is getting spark. The carburetor doesn't look too complicated, it is only ~3" long. It has a butterfly valve on each end, and I sprayed through the valve, and through the nozzle that hooks up to the gas tank. On the bottom of the carburetor it has something that looks like a little plate, that is attached with 4-6 little allen head bolts. I hesitate to take it off, as I'm not sure what will pop out of there.
Any other advice as to what I can do to fire it up? I have left fresh gas in the tank this evening, with the hopes that it might dissolve whatever is preventing it from getting a good stream of fuel. Thanks again, Richard
Until you mow over the cord. They do have cordless electric mowers, though.
I would never give up my gas mowers, though. Mowing the lawn is a boring, annoying chore and the only fun I get out of it is getting out the ear protection, and firing up the old gasoline engine and pissing off all the environmental greenies that live on my street and mow their lawns with manual push mowers. (or electrics)
A 3.5HP Briggs and Stratton vertical drive with a 20 year old rusted out pancake muffler announces to the world in no uncertain terms that a Real Man is doing his Saturday civic duty to beautify the neighborhood.
Ted
I think the ideas that were floating around here werent to rebuild the entire carb. Just blow it out with a little carb cleaner will usually do the trick.
What you describe is basically boiling out the carb with chemicals. (dangerous shit too, lots of cancer in that stuff) Handle with care and dont gargle with it.
If I had carbs that had plastic attached to it and I wanted to clean out, I would take an old heating pot (the ones you just add water, plug in and wait to boil) add some wisk, heat it up and put the carb into that. The hot water with a detergent would make it look like new. I would ONLY do this to aluminum carbs with minimal steel on them. In any case I would boil them and then spray them down with a light coat of wd40. Clean as a wistle and works great!
Anyway, with those little edgers, I would make sure that you are getting gas from the gas tank (pull the hose that attaches to the carb) If gas is flowing, great! Next on those carbs they has a primer on them. When you prime it do you see a little squirt of gas inside the carb right past the choke plate?
Just out of curiousity to make sure its a carb problem and not a compression problem did you use some starter fluid to get this thing running at all?
Thanks so much for your help. To answer your question, this carburetor doesn't have a primer, that I know of. My lawnmowers have a little bulb that you squirt to prime the carburetor, but there is no bulb on this edger. I haven't tried any starter fluid, but I'm sure that I'm getting a good spark. I don't think that compression is the issue, because it ran fine before I put it away, and unfortunately, I had left it with gasoline in the tank for a couple of years before pulling it out last week and discovering that not only did I not empty the gas tank before putting it away, but I also had not added any additive to prevent it from gumming up the carburetor. I'll pick up some starter fluid today and squirt it in the spark plug hole, to see if it will run with it.
Just squirt a little gas into the carb intake. That always does it for me.
Bob
Just spray some starterspray in the air-intake and crank it. Just curious, when you tried to start the engine, and it won't run, is the sparkplug wet afterwards? Yes? Old fuel or so. No? No gas....
Well, folks, the saga continues.The first thing I did tonight when I got home was to squirt a little bit of gasoline in the carburetor(where the air filter connects). After many cranks, nothing. So, I removed the spark plug, and dribbled a little bit of gasoline in the spark plug hole. Put the spark plug back in, and VOILA! It fired up, for around
5-110 seconds. Ran like a top, so I knew there was no problem with the spark, timing, or compression. So, once more I took the carburetor off. I removed the adjustment screws, being careful to count the turns, so that I could get them back in the same place. I then blew carburetor cleaner through the holes, then replaced both screws (counting the turns so that I could get them back in the right place). I then turned the carburetor over, and removed the little plate that was on the bottom of the carburetor (held on with 4 allen screws). Inside I found what looked like a tiny black mesh screen, which I gently partially removed, then blew carburetor cleaner in there and made sure that the whole area was clean. I then put the screen back on, put the bottom piece on (with the 4 little allen screws). Reattached the linkage and bolted it back onto the edger. I cranked it up, and again, nothing. I once more removed the spark plug, and poured a little gas into the spark plug hole, and once more it fired up, for a few seconds. I'm kind of at my wits end. Does anyone have any suggestion of something else to try? Clearly there is an issue with the carburetor, but I have had it all apart, and it looks clean to me. Thanks in advance for your help, Richard
Hit it with a little starting fluid and see if she fires. If she doesn't, then that rules out bad gas / gummed up carb.
Timing could be off (sheared soft key) or plug could be fouled.
Small engines are relatively cheap. You might be better off buying new model...
You need to move some fresh fuel thru the carb; if you run the engine for a few minutes it might flush some of the goo out. If it were 4 cycle I would idle it with an unlit propane torch in the inlet, but
2-cycle needs lubrication. Maybe start it with gas in the plug hole and spray a mist or fine stream in the intake to keep it running for a minute.A better idea is to take the carb COMPLETELY apart and clean it.
You have a small diaphram on the buttom of that carb.
There could be a pinhole leak in it. I would say take that carb completely apart and rebuilt it with a rebuilt kit (I think you said it was a sears unit so its actually pretty easy to get)
While its apart, I would use gumout and spray it in all the passages. Make sure it comes out of everywhere. Use thin wire to clean everything out.
Tom
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