M4 Fuel selector Valve.

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Mog
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M4 Fuel selector Valve.

Post by Mog »

So my airplane appears to have a leaking fuel selector valve. The leak is not bad, just a slight bit of fuel on the shaft. From what I can tell it’s just a simple Weatherhead 3way valve as found at Aircraft Spruce for $29. But of course Spruce says “Not FAA approved”. Does anyone know if this Weatherhead valve is correct or not. It’s worked for this long so I don’t see a need to install some overly complicated new valve.

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Duane
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Re: M4 Fuel selector Valve.

Post by Duane »

Weatherhead is one of the valves on our print. However, we do modify them according to what engine you have. The 210 already has an off position in the shut-off valve, so the fuel selector can not have a separate off position.

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Mog
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Re: M4 Fuel selector Valve.

Post by Mog »

So I don’t mind donating to Maule when I need parts, but the Weatherhead is about $30 from Spruce. And the same part from Maule is $200. I understand that the 210 needs to be modified, but is the 220 valve modified. If not I would rather spend the remaining $170 on other parts from Maule that I can get some enjoyment out of.

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Duane
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Re: M4 Fuel selector Valve.

Post by Duane »

The 220 uses the 10049-5 valve. All are modified, but the 210 has an additional mod to prevent the OFF position.

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riverbuggy
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Re: M4 Fuel selector Valve.

Post by riverbuggy »

What's modified about the 220 fuel selector valve? It appears to be a standard 3 way valve: RIGHT/LEFT/OFF.
I replaced mine with an Andair 3 way valve after I selected "OFF" by mistake when I REALLY didn't want "OFF".
Really got my attention in a hurry. The Andair takes 2 hands to get to "OFF". Very nice!
Ray
1970 M4-220C N2056U

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Mog
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Re: M4 Fuel selector Valve.

Post by Mog »

Andair seems comparatively priced. Is there a model approved for the 220 and what is involved in fitting.

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Andy Young
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Re: M4 Fuel selector Valve.

Post by Andy Young »

riverbuggy wrote:
Fri Jul 31, 2020 6:04 pm
What's modified about the 220 fuel selector valve? It appears to be a standard 3 way valve: RIGHT/LEFT/OFF.
I replaced mine with an Andair 3 way valve after I selected "OFF" by mistake when I REALLY didn't want "OFF".
Really got my attention in a hurry. The Andair takes 2 hands to get to "OFF". Very nice!
Hmmm...I’m not sure I’d consider needing two hands to get to “Off” an advantage when I needed “Off” in an emergency.

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riverbuggy
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Re: M4 Fuel selector Valve.

Post by riverbuggy »

It's not truly a 2 handed operation. You can easily perform a one handed operation. Just need to practice a technique that works for you. In an emergency situation I can access OFF just as quick as with the original valve. The most important improvement is you can't access OFF by accident.
Mog: there is no plumbing change. You will have to make a minor modification to the kick panel to access the selector valve handle. I will take a photo next time I'm at the hangar, and post it. I'll look up the model #, and get that to you as well. It is a great improvement over the original valve; almost like a "new" Maule.
Ray
1970 M4-220C N2056U

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Mog
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Re: M4 Fuel selector Valve.

Post by Mog »

A pic would be great. I will probably be eliminating the kick panel anyways. Just need to mount a new placard somehow.

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riverbuggy
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Re: M4 Fuel selector Valve.

Post by riverbuggy »

The Andair Selector valve that I used is M/N FS20X2-F.

Image

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Ray
1970 M4-220C N2056U

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Mog
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Re: M4 Fuel selector Valve.

Post by Mog »

Well....I installed the new valve from Maule. Now the mystery...my old valve had fuel left, fuel right and off.

The new valve has Fuel Left, Fuel Both, Fuel Right and fuel off but tanks interconnected.

This is going to change my fuel management a bit for sure. I’m not sure if this is the modification Maule does to the Valve and maybe I had the non modified valve or if back in the day the valve was configured differently. But needless to say I need a new fuel valve placard and need to address my management as the tanks can now equalize.

Do I run on both or still operate on one tank at a time?

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Re: M4 Fuel selector Valve.

Post by Kirk »

Mog, M4 & M5 were equipped with L/R/OFF valves. There is a Service Letter or Bulletin that addresses equipping with the newer L/BOTH/R/OFF valve. The change was to prevent fuel starvation in a slip when the selected tank was very low on fuel.

Both is to be selected for takeoff and landing. The rest of the time is pilot’s discretion. Most pilots report that the tanks don’t always feed evenly due to slight wing low or vent system being restricted.

Personally, if I had the newer valve I would cruise on 1 tank. That keeps me involved in fuel management, gives me something to do on a long flight and more importantly, I know how much was burned off each individual tank.

For pattern work or a local flight I would leave it in BOTH.

Kirk

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Re: M4 Fuel selector Valve.

Post by plowboy »

what do you do with the in dash fuel off business, when you change to the new valve with off in the kick panel?

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Re: M4 Fuel selector Valve.

Post by andy »

You may know this already but keep the fuel selector in Left or Right on the ground to prevent uneven ground from feeding fuel from the higher tank to the lower tank through the fuel selector and overflowing out the vent tube.

Most of the time I fly with it in the Both position until one tank is significantly lower than the other. I don't need something else to think about during a steep approach with a slip into a short airstrip.
Andy
1986 MX7-180
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Mog
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Re: M4 Fuel selector Valve.

Post by Mog »

Good call on the single tank side hill situation, I knew that but didn’t think that through on this go around. I will remember for sure...I hope!!!

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