As the main tank is draining into the header it reaches a point when they are at the same level then the header tank continues to drop as the main does. I have changed all tubing, pressure tested for leaks, checked the muffler fitting, cleaned out the bits of plastic inside both tanks from when they drilled the nipples, and still cant keep the header full as the main drops. I am almost thinking the Hiflow on the 53 isnt giving enough pressure to the main tank. Anyone having similar problems? Any ideas would be great.

I think the only thing left to try would be to try a different hi flow muffler. If everything is proper it does work as expected. It sounds like you just aren't getting pressure into the main tank. If it isn't the muffler to tank line it must be the muffler, its pressure fitting or the hole for the pressure tap.

There has to be a leak in the clunk line. If the end of the main tank clunk stays submerged,the only way air can get into the header tank is a leak in the main clunk line above the fuel level. Maybe when you put the new clunk line on it got cut? I would take another really close look at it.
Fred

I adjusted the length of the line in the main tank to ensure it would hit both far corners of the tank. The stock tubing was too long and it would get hung up in one corner.

The way the main tank tubing is offset to one side, I do understand how I could get it to reach the far side and not get hung up on the side where the nipple is? I will also redo the tubing in the main, it's def possible I nicked it or something. Unless my rubber ring isn't sealing on top, maybe I will somehow check that as well. Thanks for the suggestions.

After re plumbing all lines and press testing each line, then each tank, then both tanks under water, I am certain their is no leak. However the header is still filling full of air. I watched very close while hovering and can see a lot of air bubbles in the main tank which is causing air to go into the header. I think the fine vibration that may have caused the tail rod to break, may also be causing the air bubbles. Anyone else have the X50 torque tube that has vibration issues?

Yes, I have one. The problem I find to stop the vibration, I put 3 bearing on de shaft inside my tail boom and I drill new hole in the inside shaft because is to short. Now the vibration is resolve.

JR NEX6, JR VIBE E8, JR VIBE NEX 50

Thats exactly what I was going to do and add three bearings, but TT and the HS where I bought it said it didn't need extra bearings. Tks for confirming what I thought was an issue. I know other TT helis only use one bearing, but this heli appears to need more. Do you mean you lenghthened the torque tube by pulling the ends out a little then redrilling the screw holes? Tks for your input.

I've been watching my header tanks. No issues

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I am glad to hear that mustang, it gives me hope for this thing.

I have a header tank on my x50 (belt) and 2 raptor 30's also with header tanks. OS55 in the x50 and OS 37 in the raptors.

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I have always used header tanks on my two other 50SEs with hypers and the 30 with an os and none have this issue. I think this torque tube has got some issues. Breaking the tail rod, horrible noise in the tail above 1700, which some are calling the woo woos and bubbling ++ in the fuel.

Did you convert it from belt?

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No I built it from a new kit. It went together fairly well. I have built quite a few Rappys, and this is the only one I am having these issues with. On some other forums, others are having quite similar issues.

I know people are converting from belt to tt. May want to post an ad for the parts to convert yours to a belt either as a test or for good. My concern when I bought the belt version was static but I am convinced it is no issue. I put my 2.4 antennas in fuel tubing to help isolate them as well. Though I have tt drive and wire drive helis, I prefer the belt.

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I was thinking about going to a belt due to the problems, I just really wanted to have a torque as well as my other belts. I have been trying to get some help from the HS as well as TT, so I will continue to try and fix this thing for a bit more.

Danorn

Did you center the shaft bearing on the shaft or is it offset at 350mm?

as posted by someone else.

There has to be a leak in the clunk line. If the end of the main tank clunk stays submerged,the only way air can get into the header tank is a leak in the main clunk line above the fuel level. Maybe when you put the new clunk line on it got cut? I would take another really close look at it.
Fred

The bearing on the tail shaft was installed exactly 350mm as incicated in the manual. The wobble on the heli starts at around 1500 and doesn't really stop until 1950 or so. Others with this problem are saying it’s due to the very stiff dampers. This wobble and another very sharp fine vibration is causing extreme bubbling in the main tank and as the main tank drains, I can see the clunk actually in air bubbles and this is causing the header to drain down as fuel is not being delivered properly.

I would say it's the torque tube drive, because the X50B uses the same dampers. I would try what Quebec X50 did with two or three shaft bearings.