Defuel every day?

[brunobl]

Hi,

I am just about to get into gasser helis, and will probably have lots of questions. Please bear with me.

I'm used to defuelling the nitro helis at the end of a flying day. It is generally agreed that methanol and/or nitromethane will damage fuel tanks, lines and filters if fuel is just left there.

Is that so with gasoline? I imagine one side-effect of not defuelling would be the gradual evaporation of the gasoline, leading to an ever-increasing oil content in an unattended fuel tank. But even then, I guess that a weekly use of the heli should leave enough new fuel in the tank, so that hopefully evaporation should be of limited concern. How about other ill-effects? Will the prolonged exposure to undrained fuel damage anything? Do you guys defuel your gassers every day or only if you know you won't be flying for a while? What is a reasonable time frame to leave the heli fueled?

At least one manufacturer recomends not using "T" fittings in the fuel line (like those found in nitro helis) and making instead, one uninterrupted line run from tank to carb (to avoid air leaking in). They go on and say that in the event of defuelling, it should be done by removing the line from the carb (as opposed from using a "T" fitting). I assume then that defuelling is less frequently done in gassers (connecting/disconn would start to damage the fuel line end?) than in nitro helis.

Any light on the subject? How often do you usually defuel?

[flyinfool]

I only defuel during each flight.
The gas will not evaporate any faster from the fuel tank than it would from a properly vented fuel jug.
The fuel line will harden over time, just plan to replace all lines on the heli during your spring tuneup every year.

[brunobl]

Thanks.

Seems then that gasser helis don't need to be defuelled any more than full size aircraft or cars, then (never during day-to-day ops, perhaps so for maintenance). Good to know, that is yet another advantage of gassers as compared to nitro. Gee, there must ba a catch somewhere. Can it be that there are only good news in switching to gassers?

I've made up my mind, will take the plunge... but at the local flying field (no gassers there) people look at me like I was an E.T. every time I mention gassers. Go figure.

[Rodney]

Try the Colman fuel versus gas. Cleaner on your skin and less fumes to deal with.

[Craig Seay]

I always liked using aviation fuel. I don't have a gasser heli yet, but do have several large scale planes. Use synthetic oil and you don't have any smell and the engine stays nice and clean on the inside. Aviation fuel doesn't spoil like regular gas either.

my2cents

[Rodney]

Havent thought of that Craig. Thanks.

[PaulH]

If your gas spoils, it means you're not flying enough. :lol:

[rbort]

Yes I do defuel at the end of the day. There isn't much fuel left in there anyways as I burn most of it but a 1/4 tank in a flight usually, but if you don't defuel when you handle the heli to put it in and out of the car/trunk, etc fuel can spill out. This is expecially true for me as I lay my helis down on their sides and while putting it in the back of my truck or car trunk I flip it around in different orientations while trying to get it in there.

Also I don't like having fuel in the house anyways. It doesn't hurt to defuel and the gas container is sealed versus the heli gas tank which is vented to the open air. A heli with fuel in the tank in a hot location will evaporate fuel more quickly and smell more as well.

Due to the fact that I defuel (probably helps), I store the models in the basement and I don't smell any gas unless I am taking the fuel lines off or working on the carb or something like that.

I always fuel from the return line and defuel from the carb inlet line (with no T's).

-=>Raja.

[Craig Seay]

You are right Paul, I don't fly enough. :( Wish I had more time for flying. But life seems to keep getting in the way. You know, job, family, and just stuff. I also defuel what might be left over at the end of the day but still like the aviation fuel for the lack of smell. It also doesn't have other stuff in it like regular gas does that tends to gum things up. I have noticed that whenever I convert an engine to avgas I have to slightly bend the pump actuation lever in the carb down so as to not let the main jet pass as much fuel. I think the avgas must be "thinner". Anyway, it works and runs great and doesn't smell up the house.

[brunobl]

Thanks guys,

Some good input there.
Unfortunately we don't have Coleman or similars here. I'll be stuck with either auto gasoline (and the need to remove the 20 to 25% alcohol premixed in all Brazilian auto fuels) or aviation fuel, which I am kind of fond of using.

FWIW, in another forum there has been an extensive discussion regarding aviation gasoline, its octane rating and lead content. I ultimately emailed Zenoah about the issue and they replied saying it is harmless to their heli engines.

Raja,

I always fuel from the return line and defuel from the carb inlet line (with no T's).

Won't this force the fuel into the carb during fuelling? I thought that the gas-enabled fuel line was more rigid than the nitro silicone tubing, making the use of those pinch clips more dificult.

I'm in totally new territory for me here. It is funny that once we venture into another variation in ths hobby, we become newbies again, back to learning the most fundamental, basic stuff. I've been flying RC airplanes since 1976, just started with helis less than a year ago, will be starting with gassers in a short while. This is going to be fun! :D

Raja... please save one of those electron-moving beauties for me. I'll need one soon :!:

[DebianDog]

I pull the fuel tube off the carb if I am going to fill the tank. I keep my bird hanging on the wall in my house so when I am done flying I de-fuel. But if I am at a fun fly or other event I just leave it loaded.

Do you de-fuel your weed eater when you are done? No. Does it always start. Yes. Like Stator Gator says, "A Gasser is a glorified weed eater, nothing more". :lol:

[rbort]

No the fuel will not flow into the carb as:

a) the carb has a valve that opens and closes to pump fuel, and with the engine not running no fuel will flow

b) there is a vent line in the tank and its alot easier for air to escape out the vent rather than put force on the carb to get fuel in it.

Debiandog:

Its not a good idea to fuel from the carb line IF you have a filtered clunk such as the ceramic ones in the tank. That way all the debris will go right back into the carb when you run the engine. If you have a non filtered clunk, then you need to fuel past the filter (if you have one in the line) so that no dirt will go into the carb.

Its always easiest to fuel from the return line (one way in) and defuel from the carb line (one way out), as that is the natural fuel flow and you will not get dirt into the carb while using a ceramic clunk per example.

One generator for a Spectra-g will be here for you Bruno when you are ready!!

-=>Raja.

[DebianDog]

Good to know.

No filtered clunk. It is filtered on the line (Crap Trap) and in the fueler (built in to the Jersey Modeler jug). The crap trap looks as clean as the day I put it in there. ;)

http://www.centralhobbies.com/Fuel/Images/crptrcol.gif