Silverhawk to Fab fuel leak

[RickWoodall]

So at annual I built a new FAB plate out of steel as the aluminum had some stress cracks. We reused the silvehawk gasket. I now have a fuel leak.



Due to another issue (spade connection on lightspeed loose), I had a hard time starting the plane, got it fired up but did run the boost pump longer than required. Talked to Precision today and they said the only way to get fuel where the pics shows the blue die is from the boost pump running when engine isnt. So..i just got thinking...if the boost pump runs a bit without the engine running...the fuel just runs down and out the fab, and soaks the airfilter. Really.

Ok, so I guess I am slow. A new gasket will seal this up so I dont have an induction issue and I will order the lyco one or just get some gasket material and cut my own so that is fixed, but fuel can still bascially pour out here and pool and drip by the muffler. Does this sound right.

[brad walton]

I have a similar setup on my RV-8 and have noticed it was damp and or blue residue on the top of the FAB. I assumed the problem was fuel flow with engine not running. My solution has been a change to my start procedure. I crac k the throtle and mixture on idle cut off. Turn on the electric fuel pump until I see good presure. Turn off the pump and open the mixture until I see fuel flow for about a second or two, then back to idle cut off. Crank the engine and open mixture after it fires. This prevents accumulation in the intake but gives enough prime.

[Walt]

It's also a good idea to drill a small hole in the bottom of the filter box for accumulated fuel or water to drain out.

[boom3]

Over priming can cause this. (fuel pump on without the engine running)

Fuel can find it's way out an open intake valve then it's all down hill from there. Down the intake tube and right out the bottom.

The fuel you're seeing there is coming all the way from the top.