small engine won't start

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i have a rottotiller with a 3 h.p. briggs engine.it won't start unless i pour gas in the carburator, and then runs only till that little bit of gas is gone.any place on the web to find a trouble shooting guide or "ask an expert"........ or???????????

-- fred in wi (sixuvusmeyers@aol.com), April 17, 2001

Answers

It sounds like your carburetor is gummed up with varnish deposits, caused by letting the engine sit for a long period of time. The small openings in the jets are clogged.

These carburetors are not difficult to clean. Be careful to watch how you disassemble it, and reassemble it the same way. You can use sharp pins and a good solvent to clean and unclog all the passageways.

Good luck with it.

-- Jim (catchthesun@yahoo.com), April 17, 2001.


I think Jims right but before I'd disassemble it to clean it I'd try starting it, using Carb cleaner as a starting fluid, and keep it running like that for a short while to see if it would work itself out. Thats worked for me in the past.

-- john (natlivent@pcpros.net), April 17, 2001.

Check to see if there is a fuel filter. If there is, it is the first thing I would replace (cleaning the carb never hurts, disassembly might).

-- Lynn Goltz (lynngoltz@aol.com), April 17, 2001.

I would go with Lynn's idea first, or just pull the fuel line off the carb and see if gas is getting that far,make sure there is fuel in the tank. One time I thought I had fuel in the tank and it turned out to be water. Good luck Daryll

-- Daryll (twincrk@hotmail.com), April 17, 2001.

Like the others said, it sounds like old gas setting gummed up the carb. However if you have a diaphram type carb as opposed to a float carb, it might need a new diaphram. A kit with new diaphram is $3- $4. Kit and a can of carb cleaner with the plastic straw should do th e trick. Take it apart in an old cardboard box so you dont lose any of the pieces and pay attention how it was put together.

If it is a float type carb, then just get can carb cleaner with the straw. There is a jet or a little hole that is along the shaft where the bowl attaches that is plugged. On some the jet adjustment actually held on the bowl. Look closely. Older Techumseh/Sears lawnmower engines all had float carbs and all did this if gas left in them for long time. Briggs tended to use diaphram carbs on 2 to 5 horse engines although I've seen some float carbs.

-- Hemit John (hermit@hilltop_homestead.zzn.com), April 17, 2001.



You may try shooting carburetor cleaner into the metering jets. There should be two screw jets on the carb. One will be on the side near the idle screw and there may be one on the bottom of the carb (the second one is not applicable if the gas tank is part of the carburetor). Either one should be screwed in clockwise while noting exactly how many turns are required to seat the valve (note the position of the slot on the screw head). Usually it is about 1 - 2 turns before either will close all the way. Now you have to take the valve all the way out. This way (counting the turns), once you take the valve out and re-install the valve, you will know exactly how many turns you should back the screw out once it seats, to return it to it's original position. If you take carb cleaner with the red plastic nozzle and stick that all the way in the jet opening where the valve was and give it a good spray, you may just unclog the obstruction if there is one. I have done this many times. Good luck.

-- Glenn (gj_usa1@yahoo.com), April 18, 2001.

I would like to say a great big giant THANK YOU to everyone who answered this and to the person asking to. I have had this little Mimi-tiller for about three years the last time it worked was two years ago.I read this post and got inspired well as you can guess you all helped me fix it! THANKS!!!!

-- Nan (graf_nan@hotmail.com), April 22, 2001.

If it is an older rototiller, there might be little tubes with screens on the bottom, that reach into the gas tank. (from carb bottom) If there is, you can replace them easily. Hope this helps.

-- (sdunkling@aol.com), April 23, 2001.

Nan, Way to go !!!!!

-- Glenn (gj_usa1@yahoo.com), April 23, 2001.

I had a similar problem with a small engine. Mine would not start without spraying ether into the carburator. First, before tou start tearing things apart, make sure gas is actually flowing freely into the carb. Sometimes the fuel lines get clogged near the carb or near the fuel tank. That is a common problem with smaal engines. On an engine as small as yours the fuel tank is probable mounted right above or below the carb, tough, so that may not be a problem. But, if you take the tank off, there will be two little tubes to suck up gas. Make sure those are clear with a wire or air compressor or something. If those are clear, then take apart the carb, which is rather simple in this small of a unit, and clear up all of the valves and whatnot. Use a good carb cleaner, or if you don't have any, use clean gasoline. Do not use oil, that only makes it worse. The last thing you want in your carburator is oil. Make sure there isn't any oil sitting around in there. Make sure to take note of how you took the carb apart, they can be confusing to reassemble. That will solve this type of problem 90% of the time. Another common problem with small engines is that rust is getting caught in the carb. What often happens to small engines is they get left outside in the rain, (naturally) and water gets inside of them. The water can easily settle in the fuel bowl, and if its sits for a while, it will make a whole lot of rust. The engine will run fine for a while, then the vibration will shake some rust loose, and get the carb clogged up, and it will never flow properly. To solve this, take the fuel bowl off your carb, clean out any rust with rust remover spray, and a wire brush, get the little stuff out with steel wool, and clear out the carb with wire or air or something. If all of this fails to fix your engine, make sure you have compression. To do this is easy. Take out the spark plug, and screw in a compression tester. If you don't have one, your local hardware store will probably let you borrow one, just bring the unit to them. To test the compression, screw in the tester just finger-tight, then pull on the starter cord nice and hard two five times or so. The gauge should stay at the highest reading. When you have the compression, call up a hardware store or preferably an engine repair place, and ask them what the compression should be - roughly- for your engine. Give them the brand, horsepower, and if you have it, cubic centimeters or cubic inches. Also tell them that it is on a roto-tiller. They should be able to tell you quickly with no charge. If the compression is close to what they said, than that's probably not your problem. If it is quite far off, then you should take the engine to a repair shop to have new piston rings installed. Installing piston rings is difficult without the right tools. I hope you get this engine running. I know this response might be a little late, but I just noticed it.

-- Dan Backman (hagarclaypool@hotmail.com), June 16, 2001.


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