I've got a GX160 driving a Davey Firefighter pump. It starts readily and runs fine but then starts misfiring and stops. Sometimes 30 secs, sometimes 5 minutes. Not good for fighting fires. I have had the carby apart and didn't find any blockage or sediment in the float bowl or sediment bowl. Jet and tube are clear and all holes blow through with cleaner.
What I did notice is that the sediment bowl has a very fine filter which is additional to and downstream of the filter in the tank pickup. However, this filter is not present on some web-sourced descriptions of the carby. Is it possible that the fineness of the filter is causing some problem for the flow of fuel, eg viscosity in cold weather, varnishing-out of fuel products? If so, could I not just remove it?
Thanks bigted, the fuel starvation happened again this morning with fresh fuel. Runs for 45 secs then dies. Picks up again if the choke is put on briefly, but still dies within 10 secs.
Well, I had to transfer some water this morning and so needed to run the engine for several minutes. Same problem - died after 45 secs with fuel starvation. Pulled the very fine filter out from the sediment cup and the engine then ran without stopping for the next 10 minutes, with the tank cap fully on. So, I think that the sediment cup filter has been the cause of this fuel starvation. I suspect that the fuel has got just enough viscosity to only just make it through the filter under the very small gravity pressure head from the tank, and in the cold conditions (Canberra area) the viscosity increases enough to prevent the fuel from getting through fast enough to keep the float bowl filled under full load. I use clean fuel and so I don't think that I need the sediment cup filter, so I'll be leaving it out.
