Eddie P

My Feedback: (4)

Hi guys,

I haven't operated my Supersport for six months. It has been installed in the airframe and ready to run. I changed out a fuel tank for this season, and tried to prime the pump and fuel lines according to the manual directions.

Fully charged lipoly 2 cell pack, fresh radio charge all around. About five seconds after reaching full thrust stick position I hear an electronic hum (high pitched) for a couple seconds then nothing. I suspect possibly the fuel pump may be stalled. Have you guys seen this and if so is there an easy way to get in there and rotate the pump by hand to see if it is?

Thanks gents...

Xairflyer

My Feedback: (1)

Yes you have to remember the pump is only a brushed motor, if you can turn the shaft it should sort itself out.

If not make sure your fuel valve is opening, otherwise the pump will stall trying to pump the fuel.

Eddie P

My Feedback: (4)

Without spoiling any seals, is there an easy way to turn the shaft? I'm just trying to find out how to do this without having to have the pump serviced. Otherwise, I suppose it may have to be serviced.

Wren Turbines USA

My Feedback: (39)

Eddie,

If you are using a Hausel pump, try reversing the current with a single cell ni-cad...this usually will unstick the pump!! Also, on some of the later fadec units, you must prompt the HDT off of the first display in order for the pump to prime. This is a feature Gaspar added to avoid accidental priming...

best regards,

Eddie P

My Feedback: (4)

Thanks for your help guys.

Ron, if I plug the single Nicad cell into the same spot I currently plug my 7.4 volt Lipoly in - just reverse the polarity - and accomplish the prime procedure to unstick the motor, will the reverse polarity negatively effect the ECU, as it is in essence being run through the ECU normally? Or maybe I should unplug the motor terminal from the ECU and run it that way. On second thought I like the idea of isolating the ECU from this "experiment" [:@]

BTW - I have no idea if I'm using a new type pump. It looks like a speed 300 with a sealed gearbox pump on the business end.

Jim Cattanach

Is the turbine starting on the propane ok? If the hum is present just after advancing the throttle to initiate the start procedure, it is probably either the starter motor, or turbine sticking. The fuel pump is not operating at this time.

Oops, I see you are priming the lines with the pump. Sometimes little pieces of rubbish, tygon etc clog the gears. Running it in reverse clears this.

Wren Turbines USA

My Feedback: (39)

Eddie,
By all means...unplug the pump prior to reversing the current. It sounds as though you have the Hausel style pump, so this should get you going.

best regards,
Ron

Eddie P

My Feedback: (4)

Thanks for taking the call today Ron, I'll let you know how it goes. I've flushed it with the fuel/syringe method and I'll probably run it tonight when I have time. Hopefully it all goes well and I don't need another pump!

When I removed the black rubber electronic seal on the end of the motor there was a messy tape around the end of the motor. Is this double sided scotch tape? (for when I button it all back together).

Wren Turbines USA

My Feedback: (39)

The gooey stuff inside the lower cover is simply a way to keep the cap in place. I recommend that you remove the tape and clean with alcohol, then apply a coupe of small drops of high quality silicone and let cure overnite.. Do pay attention that you do not cover the small slot on the pump, as this is for cooling!

cheers,
Ron

Eddie P

My Feedback: (4)

Ron, you have been very helpful, I really do appreciate all of it via the forum and the phone.

I think the pump is toast - I've tried running it under various voltages and have purged it with fuel via the in line and a syringe. It still may be a stuck motor but in the end I think I'm going to need a brand new fuel pump assembly. Being it's a little brushed motor I'm sure it's probably better to go with a new one since the engine depends on a good motor/fuel pump to run the engine, let alone run reliably well. I will call you Monday morning if that is best to get a new fuel pump ordered. Thanks Ron.