When connecting the UAT, do anyone ever not use the supplied threaded cap that goes over the line to the fuel pump. I tightened it as tight as I could and I'm still getting a slow leak when the plane the plane is turned upside down. I'm not sure if this cap is cutting into the tygon or not...still trying to find the exact sorce of the leak. I'm sure this could lead to an significant air leak causing flameout. Could i remove the cap and safety wire the connection? I've done this with all my other lines and have had no problem.

Thanks in advance for your help!
Chris

Yes, you could lock wire. Check the Festo with your fingers for sharp edges, nicks which would allow a leak

Dave Wilshere

I didn't think those fittings were designed for Tygon. Is the tubing dia correct for the fitting?

PaulD

3.2mm/ 1/8th Tygon fits fine, though I use 4mm OD SMC tube straight from the UAT to the pump on short runs less than 6".

Dave

BVM recommends using 6mm OD (4 MM ID) polyurethane tubing for the pump feed line. (It is supplied with the UAT...why not use it?).
It is possible that the nut could be cutting through the wall of the Tygon. Tygon is much more fragile than the supplied tubing.
If you replace the Tygon on that run, you should not have any leakage problems.

Thanks guys! Turns out the vent leaked a little residual fuel when I turned the plane over and it spilled onto the Tygon line making it look like the UAT was leaking. Just to be sure, I pulled the UAT out of the plane gave her another trun with the pliers and no leaks!!
The UAT came used from someone else so I didnt receive any 6mm with it. I might just give Todd at Dreamworks a call and put some 6mm on there anyway. I dont like how I cant get that cap screwed all the way down anyway.

Any advice on where to place the vent? I've heard to loop the vent line around the highest part of the plane and then place the vent on the lower left or right ogf the fuse. Does it have to be run to the outside of the AC? I suppose there would be negative pressure from the engine running but would it be enough to affect fuel flow?

Cheers!!

Chris

Go to the BVM website www.bvmjets.com
Click on the "Tips and How-To's" button, then on the UAT Tune-Up button. It's near the top of the list of tips.
Click on the UAT instructions link, and give it a good read.
When all else fails, read the instructions.