I bet that old fuel and gunk in the fuel has, over time, clogged up certain parts inside the carburettor. Actually, to fix the problem is not very difficult at all if you're familiar with taking apart the carby very carefully. Of course you'll first have to empty out the fuel container before you begin work. Then you may need to buy some spare plastic tubing for fuel lines, just in case you need it. And then you need properly sized screwdrivers to remove the carburettor (like undoing the plate for the choke lever etc.
Disconnecting the fuel lines from the carb will be necessary...by sliding the plastic tube lines off the metal tubes. And you have to remember which tube goes to which part....very important. You will also have to use a small screwdriver to disconnect the little wire for throttle/revs control.
Then you carefully open up the top and bottom lids of the carb. One side of the carb will have a removable diaphragm that you can remove.
Then, you need to use a carburettor pressurized cleaner spray (which sprays a clear solvent liquid) into the various tiny internal pipes and things inside the carburettor. It is a good idea to use the normal precautions when handling flammable substances. It is normally quite safe anyhow...just keep away from heat sources etc. After you have given the internals a really good spray, you can even use a screwdriver to carefully remove a mechanism that includes a lever, vertical pin, and a delicate little spring inside the carb. But you must remember how to put it back in later, in the reverse order.....it is not that difficult to do. You may have to fiddle to get it back in, but it's not that hard. Anyway, with the pin and everything pulled out, you can spray the carb cleaner into the holes. The effect of the carb cleaners is to dissolve any gunk and debris that clogs the tiny little passages where the fuel is meant to run through. Also, inside the carb will be a very fine circular mesh filter thing, and you might even see brown coloured gunk built up a little bit on that, you need to spray lots of carb cleaner on that in order to get rid of it. The carb cleaner should be able to flush the gunk out from the mesh. After you've given everything inside a very good clean with the carb cleaner, you just have to put everything back together again carefully, and firmly.....but of course, don't use massive force to tighten screws. Use a fair bit of force, but not massive amount, or else you could bust the screws or threads.
The only temporary setback that you might have with the above procedure is if the gaskets or diaphragm are very old and degraded, or worn out. This would not be unusual. In that case, you would only need to bring your parts manual to the local lawn-mower shop to buy or order in replacements for those parts. A good lawn mower shop will probably have them in stock anyway.
Anyway, once you put everything back together, I bet that your whipper snipper will probably work like new again. The problem you experience is expected, because gunk from fuel will eventually clog things up inside the carb. It is just a matter of time. And if you can service the carb yourself, which isn't all the hard, except you just have to get your hands dirty a little bit, it saves having to throw money away for somebody else to do such a simple servicing.
Kenny
July 2007
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