Thruster origanal fuji robin 50hp electric fuel pump switch.do I switch it off after climb out?

[flyerme]

Hello ,as im not familure with the old belt drive robin engines im wondering do I switch off the electric fuel pump after climb out and switch back on for final ?or do I leave it on during the flight? I presumed I switch it off (as per above) but was told I should leave it on during flight by the ex-owner!( barley- licenced ----out back flyer)!!! he said he leaves in running the whole time the engine is running!

 

I would think its only to prime the engine? as my old rotax 447 just had a boat type hand squeeze prime pump - NO electric fuel pump

 

Thruster t83 -

 

 

[Wayne T Mathews]

The problem with leaving an electric pump on all the time is that it provides no indication as to whether the mechanical pump is working.David

Sounds like a reasonable generic technique to me, David...

 

Two important things to remember when dealing with and/or training people to use inflight fuel management in normal operations:

 

1/ Never give something away before you've got something -- IE: Do not close a fuel valve without having another one open. And do not turn off a fuel pump without having supply/presssure from another source.

 

2/ When ever you're changing your fuel configuration, always apply, 'Cause & Effect"... Know why you're changing the configuration (cause), and what effect it will have. Then check that is what happens. As an example: when turning off the boost pump, leave your fingers on the switch after you've turned it off, and check the fuel pressure remains in limits. If it doesn't, or the engine coughs, you can instantly turn the pump back on without having to "cat's paw" the switch.

 

Wayne.

 

 

[Wayne T Mathews]

Overly high fuel pressure can be problematic in engine failure as well.David

Sure can... Heard a story the other day about a bloke who decided to put in an extra boost pump, in parallel with the original one. Apparently the carbies didn't like it. Admittedly, that one was a high flow problem, not high pressure. But hey,,, cause and effect.

 

Wayne.

 

 

[facthunter]

What sort of engine driven pump does the Robin have? Nev

 

 

[Guest ozzie]

round mukuni pump.

 

If you are going to put a high pressure boost pump on then you will have to put a return line to the tank in and a pressure regulator valve to avoid exceeding the float needle max specs.

 

The pump that was later fitted near the tank was a Facitt(spelling) electric pump. It is a coil and plunger type. It was fitted with a pressure switch. These were fitted to the Rotax powered Thrusters. I do not remember them on the Robyn powered ones.

 

Ozzie

 

 

[facthunter]

Round Mikuni Pump. Thanks Ozzie. They should have a new kit in them every few years, and they CAN be assembled wrong. I'd operate the way David Isaac said and ensure your electrical pump does not give too much pressure ( as others have said). Nev

 

 

[flyerme]

Thanks everyone.. will run some taxi tests with the 2 fuel pumps...I'll see if she runs without the electric fuel pump. And yes it has a return line to tank and has a pressure valve fitted but I have a feeling it ran a rotax at some stage(as the manual for the plane also has a rotax manual with it?).