Poor running caused by too rich a petrol/air mixture,so either too little air (filter blocked) or too much fuel (carburetter problem). Solution is to change filter and clean carburetter. Problem seems to solve itself as petrol runs out beacause the mixture is forced to be correct, then too lean, as last fuel is consumed. This final lean running (luckily) also burns and cleans spark plug.
jdN
May 2010
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