Fuel tank

[Andy from Sandy]

After every flight on my X50 some fuel is used out of the header tank.

The other weekend I did lots of rolls and some inverted circuits. At the end of the flight I was astonished to see the header tank half empty.

I have always thought the shape of the tank and clunk location is not good for pickup.

With that said though I find it flies very well and I think it is pretty light for a 600.

I am going to try a fuel magnet and see how it goes.

What do others think and do you have a similar experience?

[MFC52]

I have had the same experience. I picked up an O.S. Bubbless Clunk and installed it this week. I am anxious to see if that works better.

[Taxus812]

If you are getting air bubbles in the fuel that header tank fuel level will lower. That means it is doing its job. (Especially if you are throwing it around hard). a lot of the guys around here have ditched the header tank for a bubbles clunk altogether

If you are not throwing it aground you could have either bad vibe or an air leak in the header tank seal (common).

[Don S]

Check the fuel line in the main tank.

[brianapp]

I get the same thing and for me it is directly proportional to the amount of time spent inverted. %100 upright header tank stays full. %100 inverted header tank is a bit below %50. It can be a stationary hover inverted with the same results. I think it is just due to the way the pick up line is placed on the tank and its angle. It is on the top, off to one side, and at about a 45 degree angle. Turn it upside down and even a thin clunk line goes up a bit before it comes back down. You can see that when turned upside down the clunk can't reach the opposite corner. I just figured that is why it is designed to have a header tank. As designed the system works fine.

[Rob43]

Mine seems to be working really well. I am using a Dubro sintered brass clunk in both tanks, Quick UK tank seals, and Hayes medium neoprene fuel line.

You're right - the X50 is a fun model to fly. Very quick and agile. I love how the TT head flies. Excellent collective response.

[Andy from Sandy]

I fitted the fuel magnet and manage a flight at the weekend. It was very windy to say the least but the magnet has definitely improved the situation. I have not tried the hayes fuel line and if that is softer than standard thin walled clunk line that would probably make things better still.

One thing that has always amazed me about helicopters is how well they penetrate into the wind. Having flown fixed wing years ago the weather here would have had us grounded for sure.

[Don S]

My header doesn't begin to empty until the main tank runs out, inverted or not.

[Vaeloron]

I was having issues like this as well but I ditched the header tank for a M.O.A.S. and I am much happier with this setup. Looks cleaner without the header tank and the M.O.A.S. felt elements appear to last much longer and handle much more abuse than the sponge elements of other fuel magnets.

[Andy from Sandy]

Originally Posted by Don S

My header doesn't begin to empty until the main tank runs out, inverted or not.

How have you got your plumbing and what type of clunk tubing are you using please?

I did a search and couldn't find a supplier in the UK for Hayes neoprene.

[Don S]

Plumbing is stock (true story), except for QuickUK fuel tank stoppers on both tanks.

[tat2spyder]

Wrap a few layers of electrical tape around the boom, where the boom braces mount. The ring that holds the boom will slide fore and aft, allow the boom to flex in high stress maneuvers. This flexing somehow causes the header to drain, even with no visible bubbles in the tank. It happened to 3 different x50s at my field and the tape fixed all three.

[Andy from Sandy]

Thanks Don. Although I see no leaks and previously I have tested all the plumbing by submerging in a bowl of water, the cost of the seals is not much so I will get some.

A few layers of tape is going to cost diddly squat so I will do that as well, thanks.

[Elgyn]

i had a split in the main tank pick-up line once. Cost me an engine from running lean but not lean enough to quit. It ran off the header tan for about a minute then the sound change and the motor self destructed before I could land. I should have clued in cause the header tank was 3/4 empty after a flight.

[Vaeloron]

I had a split line in tank once too that nearly took out an engine. It was part of the reason I ditched the header tank. First the in tank line split so I replaced it but then the header line split and thats when I went with the M.O.A.S.

[Commodore8888]

Originally Posted by tat2spyder

Wrap a few layers of electrical tape around the boom, where the boom braces mount. The ring that holds the boom will slide fore and aft, allow the boom to flex in high stress maneuvers. This flexing somehow causes the header to drain, even with no visible bubbles in the tank. It happened to 3 different x50s at my field and the tape fixed all three.

That. So hard.

When tat and Montee talked me into an x50 this april, I taped the boom right off. The clamp doesn't fully secure itself to the boom and will let the whole back end vibrate like mad.

I've never had bubbling issues.

The other thing I made sure to do was put flats on that tail linkage after hearing of them popping out. Flats and 262 loctite should keep that from ever happening.

Lastly, do you store your heli with or without fuel and is it run on exhaust pressure?

Nitro exhaust contains nitric acid as a combustion byproduct and will attack the rubber seals in your tank if they're left uncovered. Rotted tank seals can play havoc with your header and tune. That said, you've already checked the plumbing so I'm thinking back to vibes from the tail.

[Andy from Sandy]

I took the boom clamp off to apply some tape and found that the clamp had cut into the boom. Adding the tape should now stop that and a possible failure of the boom. I did find that I didn't need to do the screws up all the way before the clamp held very tightly.

Even before fitting a fuel magnet I always fill the tank after a flight. This has kept the clunk lines in good shape. With the magnet I need to make sure it doesn't dry out so my procedure will continue to fill the tank after a flight.

I have gone a couple of weeks without flying and so far there has been no leaks from around the seals.

I haven't flown in a similar manner to what prompted my first post so I don't know how well these changes have worked.

[Commodore8888]

Hovering in the front yard for a few moments should be enough to check if your fuel aeration is gone.....provided your neighbors don't mind a little feel good smoke

[Taxus812]

Originally Posted by Commodore8888

provided your neighbors don't mind a little feel good smoke

Tell them it gets rid of mosquitoes (worked for me)

[Andy from Sandy]

I put a few flights on the Raptor yesterday, Saturday and it looks like the fuel magnet has cured my problem.

After each flight I had emptied the main tank and only a very small amount was gone from the header tank.