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I have a 1995 Rans S-14 with a 582 Gray Head (65HP). Engine is water cooled. Has oil injection, electric fuel pump and std mechanical fuel pump. Has dual 9 gallon poly fuel tanks. The 582 has 311 hours TTSN. No leaks, good compression and strong performance until recent fuel issues.
Engine has been experiencing fuel starvation issues. Aircraft runs perfectly during takeoff and makes a full circuit in the pattern, then the engine dies on base or final, usually as throttle is reduced.
Cannot get the engine to duplicate the issue on the ground due to coolant temp rising to redline without airflow through the radiator.
Originally thought the issue was the primer. Original primer was leaking small quantity of gas when priming. Replaced primer with NEW. Also replaced the fuel filter. Has filters for each tank. They are see through filter and no sediment showing. After allowing the old filters to dry, I could blow a fine white powder out of the old filter.
When the engine died with the bad primer, I could not get it restarted on the ground. I primed it until gas was coming out of the carbs. It seemed to be flooded. One theory was that the air leakage around the primer allowed it carbs to flood out.
Primer was connected to the pressure side of the electric fuel pump. It was suggested that I move it to the non-pressure side of the fuel pump to avoid back pressure to the primer, so I did that.
The electric fuel pump is usually only used during take off and landing as a security backup. A test pilot turned off the electric fuel pump after takeoff and used only the mechanical Rotax pump and was able to complete 4 full circuits without any issues.
After changing the primer to the non-pressure side, the plane was flown today and the electronic fuel pump was left on in the pattern. Two engine off landings occurred with the engine starving for fuel on either base or final. Upon landing, two quick pumps with the primer allowed the engine to start and run flawlessly on the ground.
All of the fuel lines are in good condition. None are soft and do not allow the lines to collapse during flight. The electric fuel pump has a fuel pressure regulator and it is set at 4#. I have also changed spark plugs and the old ones showed ideal ignition conditions.
The boots on the carbs are good with no signs of deterioration.
Next steps may be to replace the electric fuel pump and also the mechanical fuel pump. The 9 gallon fuel tanks have gas caps with the metal external vent lines that are U shaped. I have checked them and they flow freely.
Do you have any suggestions or recommendations that you can offer to remedy this issue.
  • Re: Fuel issues with 582 Rotax

    by » 11 years ago


    Over here in the UK lots of pilots are removing the hand primers as to many pilots are suffering engine failures with them....finding the one way valves sticking and restricting the flow....it happened to me....I blame ethanol...making the valves swell...just my theory,

    Its difficult to spot this problem as the valves can un-stick by themselves when no pressure is applied,

    To prime my DC 503 I take off the bowls and manually fill them.

    Nick.

  • Re: Fuel issues with 582 Rotax

    by » 11 years ago


    Kurt,

    Sounds like you've already figured out what to do. You might check the pulse line from the crankcase to the pulse pump for air leaks or cracks. You can get a rebuild kit for the pump. You've already moved the primer bulb to the non pressurized side of the fuel line (which is where it should be). Only addition to the fuel system I can think of is a bypass line around the electric pump with a check valve in it. If the fuel system worked for 300 hours as it is plumbed, it should work again.

    Are you sure its fuel starvation and not flooding? Are the EGTs going up before the engine quits? (starvation). Is it running too cool? (flooding). You might want to check the float valves in the carbs. A little trash in the valve or a worn rubber tip on the valve can cause both starvation or flooding.

    If you want to test it on the ground, put an electric fan in front of the radiator. I use an old 12v radiator fan and shroud from a car and just hook it straight to the battery. It works great.

    Bill.

  • Re: Fuel issues with 582 Rotax

    by » 11 years ago


    Just an FYI to the midwest pilots that carry their own gas to the field. The COOP gas stations have 90 octane with NO ALCOHOL.I found it in Indiana.

  • Re: Fuel issues with 582 Rotax

    by » 11 years ago


    We are fortunate here in Australia that 90 and 98oct unleaded (without alcohol) is readily available. How long this situation is going to last is another story. Paul H.

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