Engine cut after going inverted

[Richard H]

Hi all

Was out flying on Sunday and managed to do my first flips. Now the first few where fine but on my third flight, the engine cut sharply after coming out of the flip and I had to do an auto. When looking at it, the fuel pipe had come off the muffler and had a tear in it on the end.

This happened again on my third flight, had to auto and the same happened again to the pipe.

Any ideas what may have caused this? Could the pipe have torn due to the impact of the auto as I am not very good at these yet. I broke a set of landing skids on each landing lol.

Any ideas welcome.

Thanks

Rich

[Tom Burgess]

Could the pipe have torn due to the impact of the auto

lol, I love the way you described this

So the pipe is broken each time you go inverted?

[Richard H]

lol, I love the way you described this

So the pipe is broken each time you go inverted?

Lol. Yes everytime I flipped her the heli came down and the pipe had torn on the end that goes to the muffler

[Tom Burgess]

the pipe isnt getting eaten by the main gear is it?

[Richard H]

the pipe isnt getting eaten by the main gear is it?

I don't think so. The end that split twice is tucked down the side of the frame and into the muffler. Nowhere near the main gear.

[kamikaze]

Hard to say without seeing the heli but it's most likely that the pipe routing is too tight,not heard of anyone tearing a pipe in a crash unless it takes out the muffler. Could the pipe be poor quality or perished?

[Tom Burgess]

I don't think so. The end that split twice is tucked down the side of the frame and into the muffler. Nowhere near the main gear.

i'm at a loss then, a real strange one

[Janek]

How hot is your engine?, could be you're running it very lean and therefore very hot, that might cause the fuel line to harden and crack.

[Richard H]

Decent enough pipe and only fitted a couple of weeks ago. Had about 6 or 7 flights through it. There was slack in the routing too as it makes it too awkward to fit.

Really is odd and I don't want to start flipping her again if this is going to happen everytime until I find the problem.

Tim kindly sorted me out with some pink gimpboy tubing and was fine during normal forward flight.

[Tom Burgess]

Tim kindly sorted me out with some pink gimpboy tubing and was fine during normal forward flight.

I just had to explain to my boss why I am sat here ****ing myself!! Lol

[Richard H]

How hot is your engine?, could be you're running it very lean and therefore very hot, that might cause the fuel line to harden and crack.

Not sure how hot it was but its an Align hyper 50 and the needle was at 1 and 1/4 turns roughly. Tim turned it back out to 1 and 1/2 turns as I seem to remember him saying this maybe a cause of it.

[Tom Burgess]

Strange that a lean run would cause ur fuel tube to break, and only when inverted??

One thing i have noticed, (as im partial to the gimpboy tubing lol) is that it goes bad a lot quicker than standard non gimpy tubing! kinda goes white inside, like you hands after 12 hours in a bath!

[Mike W]

Strange that a lean run would cause ur fuel tube to break, and only when inverted??

One thing i have noticed, (as im partial to the gimpboy tubing lol) is that it goes bad a lot quicker than standard non gimpy tubing! kinda goes white inside, like you hands after 12 hours in a bath!

Hmmm and what are you doing for 12 hours in the bath ?? lmao ... I use the gimpy tubing as well and its always been ok but like you say you have to change it more requently than the standard stuff .. I never heard of one splitting while inverted running .. You sure the engines sealed ok and no airleaks n e where in the fuel system ?? ... Does it only do it at a certain tank level ?? ... Strange one this is

[robgt]

everytime I flipped her the heli came down and the pipe had torn on the end that goes to the muffler

That's very odd?
I'm trying to think of a reason why new fuel tubing would do that, but am struggling??

Try swapping the fuel tube for non-gimp style tubing (you know, proper blue fuel tube ) and see if it still happens.

It could be just a weak piece of tubing?
Cheers,
Rob

[Richard H]

Mike - Tank was more or less full when doing it. Should have been no air leaks as checked all the nuts and bolts etc before coming out to fly.

Rob - Was the blue tubing that was causing me problems, but like you say, could and hopefully have been some weak tubing. Either that or my 600 was choking in flight looking at all of Tims with gimp tubing on them lol.