Boo Boo

[lv2plyguitar 172]

I have learned that the previous partial builder of my AVID installed the wing tanks on the wrong side therefore placing the fill cap about 4" away from the lexan. Also this causes me to lose about 2 gallons of fuel per tank because I cant fill them all the way. Not so much worried about the little less fuel but I have fuel spilling out during flight. I have the vented gas caps. What is a permanent fix to keep fuel in the tank and off the wings. It is very critical because the fill cap is so close to the lexan.

Definately when I get more time I am going to remove the fiberglass tanks and install plastic or aluminum if available. But for now I just want to keep her flying.

Does airdale or any supplier sell a gas cap that fixes that problem?

Thanks for input.

[1avidflyer 1983]

Wonder if you couldn't fiberglass new caps in where they should be, and remove the old ones? Might not have to do a lot of fabric patching, and it should all be over a solid surface. (the tank) Take care, Jim Chuk

I have learned that the previous partial builder of my AVID installed the wing tanks on the wrong side therefore placing the fill cap about 4" away from the lexan. Also this causes me to lose about 2 gallons of fuel per tank because I cant fill them all the way. Not so much worried about the little less fuel but I have fuel spilling out during flight. I have the vented gas caps. What is a permanent fix to keep fuel in the tank and off the wings. It is very critical because the fill cap is so close to the lexan.

Definately when I get more time I am going to remove the fiberglass tanks and install plastic or aluminum if available. But for now I just want to keep her flying.

Does airdale or any supplier sell a gas cap that fixes that problem?

Thanks for input.

[lv2plyguitar 172]

Wonder if you couldn't fiberglass new caps in where they should be, and remove the old ones? Might not have to do a lot of fabric patching, and it should all be over a solid surface. (the tank) Take care, Jim Chuk

Was just talking to brett at airdale and he was thinking the same thing, however he was wondering if I needed to get to the back side of the cap to do that which is impossible because it is inside the tank. Maybe you can help me research a little. However, I still need to solve my leaking fuel problem.

[Guest]

I have learned that the previous partial builder of my AVID installed the wing tanks on the wrong side therefore placing the fill cap about 4" away from the lexan. Also this causes me to lose about 2 gallons of fuel per tank because I cant fill them all the way. Not so much worried about the little less fuel but I have fuel spilling out during flight. I have the vented gas caps. What is a permanent fix to keep fuel in the tank and off the wings. It is very critical because the fill cap is so close to the lexan.

Definately when I get more time I am going to remove the fiberglass tanks and install plastic or aluminum if available. But for now I just want to keep her flying.

Does airdale or any supplier sell a gas cap that fixes that problem?

Thanks for input.

Very interesting and Boo Boo indeed.

Curious.....How are the fuel lines from the tanks routed? The outlets on the bottom of the tanks are opposite the filler caps on top. Doesn't this place the fuel outlets about 2 feet away from the fuselage? How has the fuel line routing been solved?

ChrisB

[1avidflyer 1983]

Just looking my Wag-Aero catalog at gas caps and necks and they show (on page 3) and aluminum weldable neck that is 2/14" in diameter. If one was to use a hole saw, maybe 2 3/16" size, you could slip this neck into the hole. Might have to file a bit, but usually the hole saws cut just a bit oversize. You could then perhaps epoxy or fiberglass the neck into place. Not saying this is the best way, but it's the one that comes to my mind right now. The price for the neck # E-448-000 was $8.40 the cap # E-482-000 was $6.95 Take care, Jim Chuk

Just reread you post and as far as fixing the leaking fuel caps, when you install the new caps, remove the old ones and patch the hole with fiberglass. Just thought of another thing. Do you have plastic caps? Wasn't Leni saying his caps leak fuel also. He had the plastic caps. The caps I mentioned from Wag-Aero are the steel ones and look like what my MK IVs have. No problem with fuel leakiing out of them.

Was just talking to brett at airdale and he was thinking the same thing, however he was wondering if I needed to get to the back side of the cap to do that which is impossible because it is inside the tank. Maybe you can help me research a little. However, I still need to solve my leaking fuel problem.

Edited 20 Mar 2013 by Jim Chuk

[lv2plyguitar 172]

Very interesting and Boo Boo indeed.

Curious.....How are the fuel lines from the tanks routed? The outlets on the bottom of the tanks are opposite the filler caps on top. Doesn't this place the fuel outlets about 2 feet away from the fuselage? How has the fuel line routing been solved?

ChrisB

Its weird because the drains and fuel line are in the right place but the filler necks are not. Could be that the tanks came that way so the guy that built the wings had no choice and didnt know better.

Just looked at the builders log and the picture of the wing tanks. Sure enough the drain and fuel supply is on the same side as the filler neck.

Edited 20 Mar 2013 by Avid Heavy

[akflyer 1427]

If the fill and the drain are on the same side, either its a boo boo from the manufacture, OR the builder cut them out and moved them (a more likely senario) so he would not have to deal with draining tanks when he folded the wings. I would look at cutting the filler neck out and moving them to the outboard side. It would not take that much glass work OR fabric work to fix it right.

[lv2plyguitar 172]

Just looking my Wag-Aero catalog at gas caps and necks and they show (on page 3) and aluminum weldable neck that is 2/14" in diameter. If one was to use a hole saw, maybe 2 3/16" size, you could slip this neck into the hole. Might have to file a bit, but usually the hole saws cut just a bit oversize. You could then perhaps epoxy or fiberglass the neck into place. Not saying this is the best way, but it's the one that comes to my mind right now. The price for the neck # E-448-000 was $8.40 the cap # E-482-000 was $6.95 Take care, Jim Chuk

Just reread you post and as far as fixing the leaking fuel caps, when you install the new caps, remove the old ones and patch the hole with fiberglass. Just thought of another thing. Do you have plastic caps? Wasn't Leni saying his caps leak fuel also. He had the plastic caps. The caps I mentioned from Wag-Aero are the steel ones and look like what my MK IVs have. No problem with fuel leakiing out of them.

What type of gas caps are on the kitfox. Can you post a picture? I am tired of this fuel issue and want to resolve it. Nothing worse than raining gas on the forest below that costs 4 bucks a gallon.

[akflyer 1427]

What type of gas caps are on the kitfox. Can you post a picture? I am tired of this fuel issue and want to resolve it. Nothing worse than raining gas on the forest below that costs 4 bucks a gallon.

The plastic cap wont rain fuel down unless the vent tube glue joint breaks loose. I took Randy's advice and reglued my tubes and now only tighten the cap until it is good and snug, but not till it ratchets. He fould that by doing this it does not break the glue joint every 5-6 times you fill it up.

The best fix is probably to get the caps that Jim listed and glass those onto the TOP side of the tank and then have the solid metal cap on it. I never had an issue with the kitfox metal caps leaking unless the cork gasket material got worn out, but that is easy to inspect and replace.

[lv2plyguitar 172]

The plastic cap wont rain fuel down unless the vent tube glue joint breaks loose. I took Randy's advice and reglued my tubes and now only tighten the cap until it is good and snug, but not till it ratchets. He fould that by doing this it does not break the glue joint every 5-6 times you fill it up.

The best fix is probably to get the caps that Jim listed and glass those onto the TOP side of the tank and then have the solid metal cap on it. I never had an issue with the kitfox metal caps leaking unless the cork gasket material got worn out, but that is easy to inspect and replace.

:BC:/>

THanks Leni. The AVID Awaits your flying it. Randy has put about 4 hrs on it.

[akflyer 1427]

THanks Leni. The AVID Awaits your flying it. Randy has put about 4 hrs on it.

It is going to be tight this time home.. I am working over a week and am headed to the lodge for a couple birthdays back to back so I may only have one or two days I could sneak off to fly. I will call you when I get a time frame nailed down. The only other option for me this time in would be to swap planes and take it to the lodge and do some flying out there to put hours on it.

[lv2plyguitar 172]

THanks Leni. The AVID Awaits your flying it. Randy has put about 4 hrs on it.

Okay this is the neck and cap assembly I want to use. Do any of you see a problem? It has the flange to glue and glass to the tank.

http://www.acsproductsaz.com/10610.htm

THanks

[akflyer 1427]

Okay this is the neck and cap assembly I want to use. Do any of you see a problem? It has the flange to glue and glass to the tank.

http://www.acsproductsaz.com/10610.htm

THanks

I would be hesitant to use a fuel cap that does not have the goose neck ram air tube in it. The steel cap that Jim refered to can have the tube braised or welded into it. The guy that had my avid before me did not have the ram air tubes in the plastic caps and said he never had an issue with the engine running out of fuel but I am hesitant to try it. I may put one on a tank and take it up and try running on that tank to see if it draws fine over time, but there was a reason that the factory put out the service bulletin to modify the caps with the ram air tube in them.

Just my .02

[1avidflyer 1983]

I read in one of the Avid newsletters why they went to the ram air vented tubes. One of Avid's main guys was flying behind a 582 to Oshkosh and his fuel pump quit. He had to put the plane down in the mountains somewhere. I could find the newsletter if need be, but that's how it came about. The ram air pressure will keep the fan turning. (that's kindof nice) On my first MK IV, I drilled out the metal caps and epoxied in 1/4" aluminum tubes. They worked fine. I also used those caps without the tubes for a long time with out problems, although shortly after I stated to fly the plane I had a fuel filter between the wing tank and header tank plug to where I had to land in a neighbors hay field. (It doesn't take much to stop gravity feed) If I had had the vented tubes then, it may have pushed enought fuel through the filter to keep it running. Take care, Jim Chuk

I would be hesitant to use a fuel cap that does not have the goose neck ram air tube in it. The steel cap that Jim refered to can have the tube braised or welded into it. The guy that had my avid before me did not have the ram air tubes in the plastic caps and said he never had an issue with the engine running out of fuel but I am hesitant to try it. I may put one on a tank and take it up and try running on that tank to see if it draws fine over time, but there was a reason that the factory put out the service bulletin to modify the caps with the ram air tube in them.

Just my .02

:BC:/>

[jlpeet 2]

I had the same problem on the last avid I built, but I saw the problem when I put the tank in the wing with the cap to the wing tip the twist in the tank was wrong. I had to move both cap and drain. Not hard with the tank out of the wing. I cut a square.around the cap,when you have the cap out add a lip 3/4" or so on the under side. Then you cut the same size square where you want the cap to be slip the cap in the new hole a little resin and pull the cap up tight,I had the tank upside down until the resin was dry. Then a little glass on top and you're done. Hope this made sense.

Jim

Oh yeah I forgot. I had two tanks and they both had the same problem.

Edited 21 Mar 2013 by Jim123

[6320012s 12]

I had to pull out my tanks to repair a leak, and found rather than repairing the fabric, a piece of.032 Aluminum screwed to the cap strips made for a repairable installation. At the leading edge, leave a bit of the plywood in place to screw the aluminum to.

[EDMO 1078]

What type of gas caps are on the kitfox. Can you post a picture? I am tired of this fuel issue and want to resolve it. Nothing worse than raining gas on the forest below that costs 4 bucks a gallon.

All of the Kitfoxes I have owned or seen have the steel bayonet-type caps - Just like the old-fashoned ones that the cars and Pipers used. You can buy a cap at local autoparts that will fit the Kitfoxes or Pipers. Anything from plain galvanized with a handle on top, to pretty chrome slick ones. About same price as Spruce.

Just make sure you get the UNVENTED, and then put a bent copper or steel tube on it. All of the newer ones I have seen have neoprene gaskets, unlike the original Piper caps with the tubes already on them with cork gaskets, for about .....sit down.....$110 each!!!! I have a pair of those too.

I like to thread the tubes and put a nut above and below the cap, and epoxy it too.

I even found some electric light sconces that have goose-neck 3/8 diameter tubes that could be used, and already threaded, but they may not be tall enough for a tail-dragger with full tanks when folded.

ED in MO

Edited 21 Mar 2013 by Ed In Missouri

[dholly 718]

My KF-3 had the pitot ram on the fuel cap when I bought it, and I've seen other similar. To the best of my knowledge it was oem on the model 3.

[1avidflyer 1983]

If you pay attention, you learn something every day. A few posts back, someone (Avid STOL HH) asked to see the metal caps on other planes. I brought the camera with me when I went to go flying to get some pics for him. I took some of my MK IV caps with the ram air vent tubes, then a couple of the cap on my C model HH wings. I knew those caps were plastic. Low and behold! those caps were close to the fusaloge just like yours are. Glad you brought up the problem you were having with them, I think I will replace the caps to where they should be before I recover those wings. Funny how if your not looking for something you maybe don't see it. I've looked at those wings various times, but never noticed the caps location till today. Well here are the pics... Put another 2 hrs on the MK IV today, helping my friend master the taildragger. He just got his Private a few months ago in a 172 and wants to start flying the Avid... Big change. He showed lots of improvement today. We are on skis and landing on a packed strip on a lake. Take care, Jim Chuk

[lv2plyguitar 172]

Well found out why fuel was pouring onto the wings. The plastic self vented caps have a gasket ring that is supposed to seal to the filler neck when screwed on, however my filler neck was not protruding above the wing surface therefore when the cap was screwed down the gasket did not even make contact with surface of the wing. Fuel was being sucked out of tank through through the threads of the gas cap. I doubled the gasket to make sure a seal was taking place on the surface of the wing. Lo and behold after flight testing no leakage and lots more gas in the tank after a trip.

When I relocate the filler neck to the outboard side of the tank I will put the ram air on at that time. For now this will get me through phase 1.

Thanks for all the input.

[EDMO 1078]

Well found out why fuel was pouring onto the wings. The plastic self vented caps have a gasket ring that is supposed to seal to the filler neck when screwed on, however my filler neck was not protruding above the wing surface therefore when the cap was screwed down the gasket did not even make contact with surface of the wing. Fuel was being sucked out of tank through through the threads of the gas cap. I doubled the gasket to make sure a seal was taking place on the surface of the wing. Lo and behold after flight testing no leakage and lots more gas in the tank after a trip.

When I relocate the filler neck to the outboard side of the tank I will put the ram air on at that time. For now this will get me through phase 1.

Thanks for all the input.

Your double-gasket may have stopped the leakage - but could it also stop the gas flow by not venting? I wouldn't wait to put the vent on the cap - and why are you going to change the location of the cap now when you have your problem solved? The vent tube should let you fill your tanks full without leakage.

Ed in MO

Edited 22 Mar 2013 by Ed In Missouri

[lv2plyguitar 172]

The vent was not isolated by sealing the main neck of the gas cap. Now it is. The vent only allows air in and not out therefore if a vacuum is created on the wing the fuel cannot come out. Because of the dihedral of the wing I am loosing fuel capacity because I cannot fill all the way. I am loosing about 6 gals capacity overall.

Edited 23 Mar 2013 by AVID STOL HH

[EDMO 1078]

The vent was not isolated by sealing the main neck of the gas cap. Now it is. The vent only allows air in and not out therefore if a vacuum is created on the wing the fuel cannot come out. Because of the dihedral of the wing I am loosing fuel capacity because I cannot fill all the way. I am loosing about 6 gals capacity overall.

How much Dihedral do you have? The standard Kitfox has only about 3/4 inch to 1 inch per 4 feet, this would only put about 1/2 inch more in your tank. What if your plane is parked not level?

Hard to imagine 6 gals less, but guess you know.

The Kitfox tank necks stick up about an inch or more above the tank, and the cap does not protrude into the neck - guess that would be better for full tanks, but again, tanks dont stay level in flight, so must be sealed with gaskets and have a positive vent pressure from tall ram tubes.

ED in MO

Edited 23 Mar 2013 by Ed In Missouri