Proper fuel caps? M7

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asa
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Proper fuel caps? M7

Post by asa »

When I purchased my M7, it came with a couple spare fuel caps. I realized that not all the fuel caps are the same, there are two types. One type says “vented” and one says “pressure vacuum”. Also, one type has four “tangs” (two sets of two, offset slightly, so you have to do a full revolution to secure), and the other type just has 2 tangs.

Are one of these for the aux tanks and one for the mains? Is one type for all the tanks the the previous owner just threw in some rando caps?

There’s so much red paint caked on them I can’t imagine the vented ones actually vent.

My hypothesis would be that the aux tanks need vented caps and the mains don’t?

Thanks for any info,

Asa

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Andy Young
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Re: Proper fuel caps? M7

Post by Andy Young »

Per Maule, the correct caps are Stant #10640, which are available at most auto parts stores for about $8. Two tangs. For some planes, they need to have their lip cut down a bit to clear the screws that hold the trim ring, or to clear the sheet metal. If you buy them from Maule, they will already be cut down, saving you the trouble. Come have a look at mine if you like.

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Re: Proper fuel caps? M7

Post by asa »

I like $8.

Same for all 4 caps?

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Re: Proper fuel caps? M7

Post by Andy Young »

Yup

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Re: Proper fuel caps? M7

Post by asa »

Actually $6.50 at O’reilly.

Thanks!

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DavZeeMXT
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Re: Proper fuel caps? M7

Post by DavZeeMXT »

Usually it’s the rubber gasket that gives out before the metal cap gets “misplaced” somehow. I always give mine a shake when I’m checking the fuel to make sure the vent thing inside is free.
1997 Maule MXT-7-180A
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Re: Proper fuel caps? M7

Post by andy »

Keep the gasket lubricated or it will eventually tear.
Andy
1986 MX7-180
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