Fuel ON or OFF?

[Auster]

After shutdown I mean. I'm wondering what other Kitfox pilots pilots do - leave the fuel tap on or turn it off after flight? I've always left it on because there seems to be no safety or maintenance advantage to turning it off. It is a 912 ULS powered S5 with the standard on/off tap supplied in the Skystar kit. I occasionally turn it off after engine start just to check that it is operating smoothly and is actually stopping the engine. What do others do?

Nice weather here in central Europe so today a flight to rack up my 500th Kitfox landing :)

[Delta Whisky]

My procedure is to turn off all three fuel valves. The (my) theory being that it eliminates/minimizes constant pressure on the floats and will minimize any leaks that might occur during the aging process. Thinking it might not be a good idea to shut them off during a short fuel stop, I once experienced the down-wing-massive-overflow on a ramp where the slope was barely noticeable. Now they get shut off and my personal rule is to follow, without exception, the good ole start up checklist.

[desertdave]

I shut mine off and "Fuel On" appears twice in my checklist.

[Maverick]

My procedure is to turn off all three fuel valves. The (my) theory being that it eliminates/minimizes constant pressure on the floats and will minimize any leaks that might occur during the aging process. Thinking it might not be a good idea to shut them off during a short fuel stop, I once experienced the down-wing-massive-overflow on a ramp where the slope was barely noticeable. Now they get shut off and my personal rule is to follow, without exception, the good ole start up checklist.
Ditto exactly!

[GuppyWN]

Unless there is a safety reason to turn it off, I see no upside.

[Auster]

I shut mine off and "Fuel On" appears twice in my checklist.

Dave yes "Fuel on" also appears twice in my checklist even though don't shut mine off and can't yet see the benefit of doing that. Except I do worry about the valve not being moved and maybe the seal hardens and eventually fails when I really do want it to turn off e.g. a fire/crash situation. So I sometimes cycle it but otherwise leave it on.

[Av8r3400]

Unless there is a safety reason to turn it off, I see no upside.

Agreed.

I only shut mine off when needed for maintenance or emergency. I see more valid reasons not to shut them off.

[alexM]

My procedure is to turn off all three fuel valves. The (my) theory being that it eliminates/minimizes constant pressure on the floats and will minimize any leaks that might occur during the aging process. Thinking it might not be a good idea to shut them off during a short fuel stop, I once experienced the down-wing-massive-overflow on a ramp where the slope was barely noticeable. Now they get shut off and my personal rule is to follow, without exception, the good ole start up checklist.

I haven't run any plumbing yet, but 3 valves? I only know of the one on the center console.

[Av8r3400]

I haven't run any plumbing yet, but 3 valves? I only know of the one on the center console.


It is advisable to put a shut off valve on each wing tank. For nothing else it makes maintenance easier if you need to work on a tank.

[jiott]

I used to leave my fuel valve ON all the time, but now turn it OFF after the day's flying. What changed my mind is someone left his ON and some debris or something caused his float needle not to seal off and the next morning he found a large puddle of gas under the engine where it had run out the overflow tube during the night. Imagine what a spark could have caused when he turned on the lights or something with those gas fumes filling the hangar. I know its a long shot but it very well could happen, so I now turn mine off. Its easy enough to do.

[Auster]

I used to leave my fuel valve ON all the time, but now turn it OFF after the day's flying. What changed my mind is someone left his ON and some debris or something caused his float needle not to seal off and the next morning he found a large puddle of gas under the engine where it had run out the overflow tube during the night. Imagine what a spark could have caused when he turned on the lights or something with those gas fumes filling the hangar. I know its a long shot but it very well could happen, so I now turn mine off. Its easy enough to do.

Thanks. Certainly something I hadn't considered.

[airlina]

I haven't run any plumbing yet, but 3 valves? I only know of the one on the center console.
Alex , this is from a discussion from an old thread on why I installed two tank to header fuel valves


Hi Ross, It is a bit disconcerting for new kitfox pilots to watch the fuel drain from one tank - you always wonder will that tank run dry or when does the other tank start feeding? I know that was my reaction when I started flying mine 12 years ago. Also walking around at OSH one year ,I saw fuel peeing out of one of the fuel tank vents on a freshly fueled kitfox. The plane was parked on a slope and the high side tank was pushing all his expensive fuel out of the low wing. So how to fix this-well John covered it pretty well, the fix for me was to install 2 inline fuel shutoff valves on both tank to header, fuel lines. This allows several things 1) inflight fuel balancing, especially helpful on cross country flying. Before the fuel valves were installed, I would fly uncoordinated to try to balance fuel loads, now I shut the appropriate valve and burn from the heavy tank. 2) Shut one of the valves after parking on uneven slopes so your kitfox doesn't pee while you are away. 3) maintenance- sometimes during maintenance work I need to isolate the wing tanks from the fuel system, and these valves allow this . Now for the cautions! Make sure the valves are large enough and do not restrict flow(good idea to redo fuel flow check at engine after installation). At my advanced age it is easy to forget I shut one or both valves, so whenever I touch one of them I have a big red flag (one of those remove before flight jobbies) that I clip on my throttle be it on the ground or inflight. Also to avoid inadvertent movement ,I made a simple locking device on each valve. Have fun Bruce N199CL

[Dave S]

Question for Larry,

You mentioned it is advisable to have shutoff valves for the wing tanks - do you have them on Mangy?

If you have them, where did you get them?

[Av8r3400]

Yes I do have a valve at each wing tank. I sourced them through the aviation department at my local ACE hardware. Just a standard ball valve.

I plumbed my system with a short length of fuel injection hose from the tank to the valve, which is solid mounted to the airframe, then hard lines to the header tank. Then hard line from the header to the aux facet pump and on to the main shutoff on the firewall (remote operated ball valve). At that valve I have a bulkhead fitting through the firewall to fire-sleeved fuel injection hose on the engine side to a metal bodied filter just before of the mechanical fuel pump. From the mechanical pump to a pressure sensor and flow sensor and finally y-ed to the carbs, with no return.

Wing to header shutoff - Link (http://avidfoxflyers.com/index.php?/topic/709-classic-iv-restoration/&do=findComment&comment=26776)

Main shutoff - Link (http://avidfoxflyers.com/index.php?/topic/709-classic-iv-restoration/&do=findComment&comment=22766)

[Maverick]

I bought some ball valves off Amazon
https://www.amazon.com/gp/product/B074386FSP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I put them on the vertical that runs behind the pilot/passenger seats right above filters that I also bought from Amazon
https://www.amazon.com/gp/product/B004AJ182Q/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I used yellow Tygon fuel line. There is a short piece between the bottom of the valve and the top of the filter so that I can disconnect the fuel line and attach a hose for draining the tanks at annual. The valves and filters are secured to the vertical with UV resistant zip ties that I'll change annually.

[Dave S]

Larry,

Thanks for the detail on your system. I can see the merits of a ball valve as it eliminates any obstruction/resistance to flow compared to other types of valves.

Blue skies