New Finish Kit Fuel Cap

[jsenft]

I just received my Finish kit. The fuel cap still was shipped with instructions to drill out a vent hole in the cap. I thought with the new Vent kit, also shipped with my kit, drilling out the cap was not needed.

[AZLeeJay]

I think you're right. I just picket up my SLSA and the fuel cap is not vented.

[D&M Dan]

Does anyone know if the fuel cap requires a hole drilled for venting if the new tank vent system is not utilized? I have installed the fitting for the new vent but may not hook it up at this time.

[Phantom30]

With the fuel tank vent line installed there is no need to drill fuel cap...

[skydiverlv]

Originally Posted by D&M Dan

Does anyone know if the fuel cap requires a hole drilled for venting if the new tank vent system is not utilized? I have installed the fitting for the new vent but may not hook it up at this time.

If you do NOT utilize the new vent line, the cap MUST be vented.
Is there a good reason I am unaware of why one would not use the vent line?

[DHeal]

Early RV-12 kits did not have a separate fuel tank vent line. The early design utilized a couple of holes drilled in the cap for fuel tank venting. Apparently, Van's Aircraft considers either design to be acceptable although current kits have the separate tank venting system (i.e., with a sealed fuel cap).

[D&M Dan]

Larry, l have one of the early kits and I was unsure if I wanted to add the optional venting. I think I will however so as not to drill the cap. Thank you for the replies.

[DBRuth]

I have a fairly recent kit,797 and have the tank vent. I didn't drill the vent in the cap originally. I have had three minor "events" during takeoff ,a strong fuel smell in the cockpit. The engine did not skip or stumble, just smelled fuel. I decided to drill the vent holes in the cap. I did, however drill with a #43 drill and tapped 4-40, so I can plug the hole with a 4-40 screw if I find I don't need the vent hole. I have 4 flights (6.2 hours) with the cap vented and no fuel smell yet. I will update as I accumulate more hours.

[PilotBrent]

I added the vent last year but kept the vented fuel cap instead of replacing it with a new sealed one. Interesting idea to tap it and put a screw in the hole. Advantage of vent is when filling the tank, less chance of fuel blow back (and getting on the back window) if it is being filled too fast. Doesn't entirely eliminate that risk, but improves it. If the new vent gets plugged by insects etc... I feel better having the original cap as an alternative means to vent the tank.

Saw a guy taping over an RV-12 cap at Oshkosh a while ago to prevent water from leaking into the tank when parking outside for several days. Probably only downside to keeping the vented cap.

[DHeal]

While we're on the subject of vented fuel caps, I make it a point to physically blow through the fuel cap vent holes as part of my preflight inspection and/or during refueling operations. Just making sure that no critter has taken up residence in my cap.