914 Fuel Smell in Cockpit

Hi James,

"I had a persistent minor fuel smell in the cockpit until I changed all fuel hoses to the Gates Barricade brand. I used their carburetor version, not the fuel injection version. FI hose is unnecessary unless you run FI pressures."

You are correct that FI is "unnecessary" for carburettor supply pressures however there are two additional benefits, to Gates FI hose, over the carb hose:

 # Lower vapour permeability and higher temperature tolerance.

The difference is purchase price is quite small, so if, like me, you want to use the higher standard it won't "break the bank"😈

I use only Gate Barricade fuel hose. I buy it by 25' reals since I do a lot of rubber changes. many use 1/4", 5/16" and a small amount of 3/8".  I use Gates Green Stripe 1" (25mm) coolant hose. In 25 years I've never had an issue or a hose leak.

If it's a carbed engine I use gates Barricade carburetor / vapor recovery hose. It's rated at 50 psi and since our carbed engines run around 3.5 psi - 5.5 psi there is no issue. This hose allows some stretch over some fittings where the Gates Barricade fuel injection hose (100 psi rated) does not. I found when pushing on fuel injection hose over some fittings (i.e. barbed fittings) that because it has very little give at times shaves off some of the inner hose liner which floats downstream.

1/4" = 6.3 mm,,,,,  5/16" = 7.9 mm,,,,,  3/8" = 9.5 mm

G'day Roger,

I agree with most of what you have said but have some alternative thoughts on the following;

"I found when pushing on fuel injection hose over some fittings (i.e. barbed fittings) that because it has very little give at times shaves off some of the inner hose liner which floats downstream."

I think this advice is good for old style barbed hose fittings, especially if the hose is removed/refitted;

I would strongly advocate for the modern push on hose fittings similar to this;

Assuming correct hose ID to fitting OD almost guaranteed not to leak and very very unlikly to cause internal damage to hose.

Multi barbed hose fittings are a hangover from the past and should not be used in aircraft applications.😈

Sean Griffin wrote:

Hi Dave,

Possibly over full tank(s) venting in climb.

I have both wing and fuselage tanks - if I overfill the fuselage tank, I often get fuel smell, associated with climb out.😈

Several flights ago, I topped off the fuselage and wing tanks and I certainly filled the fuselage tank as much as possible.  I had a Sting S3 previously with the single fuselage tank and always filled to the top and never had an issue.

Anyway, it took a couple flights to use the wing tank fuel and burn a couple gallons out of the fuselage tank.  Today’s flight was odor free!  So it was operator (overfill) error.

Now on to my prop pitch question…….