Primer Fuel Line Failure

[Mark Keneston]

I just noticed that the break in the copper tube occurred at the smallest bend radius.
I wonder if that point were over bent or some how stressed too much?
I can't see any damage to the tube in the picture but something caused it to break where it did.
Maybe defective tube?

Seastar can you send me any pictures of this, the loops, bends and clamps? Please. If there is excess tubing and limited clamps, then vibration can cause a stress fracture. As for the no start issue, where are you located? Aircraft inside or tied outside? Also is this a factory built plane or an EX kit built? How many primer ports do you have? Our FX sits in a hanger at 45-50 degrees and I can just stroke the throttle 2-3 times and it fires up.

im trying to help just need more info please. Thanks Mark. Yankee 1

[Mark Keneston]

Seastar can you send me any pictures of this, the loops, bends and clamps? Please. If there is excess tubing and limited clamps, then vibration can cause a stress fracture. As for the no start issue, where are you located? Aircraft inside or tied outside? Also is this a factory built plane or an EX kit built? How many primer ports do you have? Our FX sits in a hanger at 45-50 degrees and I can just stroke the throttle 2-3 times and it fires up.

im trying to help just need more info please. Thanks Mark. Yankee 1

Also looking at Turbo’s pictures it looks like far too much line and the loop itself did not look clamped. That vibration surely could fracture that loop. I also know many who will prime two cyls instead of just one. MK

[seastar]

I will ask again, what is the correct solution to this serious problem?
ignore it or talk about thread sealant?

[turbopilot]

I will ask again, what is the correct solution to this serious problem?
ignore it or talk about thread sealant?

Flexible braided stainless steel fuel line. Running copper fuel lines to a vibrating engine does sound a bit old fashioned.

[Daveembry]

I will ask again, what is the correct solution to this serious problem?
ignore it or talk about thread sealant?

Seems like that’s what people are on here doing....trying to help you figure it out. I believe the last post was Mark asking for some photos?

[Cubdriver2]

Running copper fuel lines to a vibrating engine does sound a bit old fashioned.

That is used on maybe every certified aircraft built, with success

Glenn

[turbopilot]

That is used on maybe every certified aircraft built, with success

Glenn

Yup all grandfathered. I have owned many new airplanes certified under the newer Part 23 regulations which if I recall happened in the 1970's. I can assure you I have never purchased an airplane certified under new Part 23 with a rigid metal line from the fire wall to the engine. While I understand my CC is not a Part 23 airplane it was built in this century (2014). Makes no sense "today" to make an airplane with a rigid metal tube running from the firewall to the vibrating engine.

[Cubdriver2]

Every airplane I have ever worked on has had a copper primer line. And not only one piece from the firewall but one piece from the primer. My yellow cubs is even longer, I have a swingout mount and a couple extra feet of copper. Only primer problem I ever had in the last 4400hrs happened last fall on a 78 year old floatplane and the primer failed to work. Who ever installed it last must have just tightened it finger tight and the ferrule fell off when it came loose. I know we have better materials today but I still trust time tested simple things that work.

Glenn

[seastar]

Thanks for the answers to my question.
I think I'll go with braided line.
Don't want to fly a fire ball!
Good luck Glenn!
Bill

[Firekeeper]

The primer is a fuel pump from the tank to the carburetor chamber. If the liquid does not return, see at what stage and where the discharge occurs in this branch.