View Full Version : vent hose plugged
I flew a tank of fuel today before realizing that I forgot to remove the fuel tank vent hose plug. Anyone know if this is harmful to the motor? I thought the vent hose had to be open in order for the motor to operate properly. It ran fine with it plugged.
cbergen
03-12-2007, 10:16 PM
It will run, for awhile anyway.... :D
I have forgotten my plug before also, I figured it out when my fuel tank looked lke a prune....... :oops:
It means you have a good strong diaphragm in your carb, it'll suck that tank right down, and no it shouldn't do any long term harm to the engine.
rbort
03-12-2007, 11:10 PM
Never use a vent plug. Someday you will forget it and it will kill the helicopter. :shock:
There is no reason for it.
-=>Raja.
Thanks, Chris. Yeah, it sucked the tank in quite a bit. The shape came back, though, after it was in the house for a while. Raja, in my case the plug is necessary. If there's any fuel left in the tank it runs out the vent hose when hung on the wall for storage.
rbort
03-13-2007, 07:41 PM
The I would say two things:
a) maybe you don't have your vent line ...wait, 3 things...
a) maybe you don't have your vent line looped 540 degrees before coming down.
b) you should be emptying the tank before you bring it home so there is no fuel, reduce smell and nothing to spill
c) if you must insist with the plug, put a red ribbon "flag" on it that says "remove before flight" as they do on aircraft. This way you won't forget it!
-=>Raja.
P.S. Look in my gallery and you will see how I loop my vent line. I also drain the remaining fuel back into the jug and purge the carburator before I leave the field.
Thanks, Raja. My vent line was not looped 540 degrees but it is now.
Even with the vent line looped 540 degrees now, the fuel still comes out the vent hose if you hold the nose of the heli up for any amount of time. Plugging the line not only prevents any leakage but also eliminates any fumes when storing it in the house. I decided to just tie a red piece of ribbon on the tail for a reminder.
rbort
03-21-2007, 08:29 PM
Its cyphoning out. It will cyphon through any loop, 540 or more turns. The loop is intended so you do not spill fuel in a flight when you and fliping the machine around and around. Having the longer looped line makes it harder for the fuel to dump out and the inflow of air from the carb drawing fuel helps as well to keep the fuel in the tank.
Now if the motor is not running and you are hanging the heli on the wall vertically with the vent nipple submerged in fuel, eventually if that or other nipples have a small air leak the fuel is going to cyphon down the loop, turn around 540 degrees and drip out. The loop helps if you are flipping the heli around, but not at all if you are storing it.
I tried to say before "why store the heli with gas in the tank"? but I think you want to do that so you need to plug it if that is the case. Personally I drain mine dry and then there is no fuel to drip and the smell is almost non-existant unless you put your nose right up to the carburator.
-=>Raja.