panzertank

i have a hobbico avistar and wonder : how do you know the fuel tank is full? it says in the manual not to fill the tank over the pressure line, but how else am i supposed to know how much fuel is in there?

DMcQuinn

My Feedback: (13)

You disconnect the overflow line (this is the one that goes from the top of the tank to the muffler) from the muffler and point it away from the plane. You fill the tank until fuel squirts out this overflow line. You fill using the line that goes to the needle valve. So every time you need to fuel up, you disconnect both lines. Then connect both lines (don't mix them up) and start the engine.

Deadeye

While the above statment is true, for those of us that burn 5 cases a year; I have found a 4 oz overflow tank will save many ounces of fuel that would otherwise be wasted. Better to be burned in the air than expelled on the ground.

meaden

I agree with Deadeye. I have a catch bottle that I connect to the muffler line when I fuel. It's another full tank of flying per gallon. At least.

somegeek

My Feedback: (2)

Muffler pressure line gets disconnected and hooked up to this catch bottle...



Pump this back into my fuel jug when cleaning up at the end of the day.

somegeek

Dr1Driver

Why not just run the catch line back into the supply jug? Eliminate the catch bottle completely.

Dr.1

Flying freak

how would this be done? i use power master and i highly drought you could get 5 fittings in that lid

- from bottom of tank to pump
-other end of the fule pump comes back to the lid
-from bottom of tank to fuel dot to use with a syringe filler
*this is what i now have*wouldnt i need 2 more...

Steven

meaden

Given the choice of keeping track of a piece of fuel line long enough to run back to the jug or a catch bottle? Catch bottle. The fitting comment is right too. You would need at least three or take the top off the jug all the time.

Square Nozzle

My Feedback: (1)

Panzertank, I don't believe anyone really answered your question. However, what is being said is that 99% of us fill the tank till the fuel comes out the muffler pressure line. I know of no reason why you shouldn't fill to overflow out the disconnected muffler pressure line. Your instructions are probably slanted towards avoiding spilling fuel overboard or filling the muffler with fuel and likely flooding the engine through the exhaust port. It will not affect the engine operation or fuel system performance if you fill to overflow. It is a good idea to catch the overflow in a container of your choice.

BillyGoat

Panzer, you’ve asked a lot of questions lately and quite honestly it worries me. It’s obvious the internet is your only source for R/C info. Most of the questions you’ve asked in this forum would be answered in just one session with a good instructor. Judging by the type of questions you’re asking (this one being a perfect example), you defiantly should have a mentor/instructor.

The part that worries me is the questions you DON’T know to ask! This sport is not forgiving to mistakes and most mistakes that can be made are detrimental to your safety as well as others. Do yourself a huge favor and find a local club and get in contact with them or even go to the next meeting. Even though flying season is likely over in NJ there will be someone that will be willing start mentoring you now, answering your questions as well as provide insight you had not even considered.

Dr1Driver

how would this be done?

Fancy filling stations not considered, this ain't rocket science. I have a supply jug and an MPI hand crank pump. There are two fittings in the supply jug top. A filling line runs from one to the inlet of the pump. A line runs from the outlet of the pump to the filling fitting. While not being used, the filling fitting is stuck into the unused supply jug fitting to close the jug to open air. When in use, the filling fitting is plugged into the carburetor supply line and the return line is plugged between the muffler vent line and the unused fitting on the jug top. If you need a pic or diagram, I can provide.

Dr.1

meaden

Fittings and catch bottles aside I think BillyGoat hit the nail on this thread. Find a club, or an RC buddy you can bounce questions off.

bkdavy

My Feedback: (1)

Two hoses from the fuel jug are all that is needed. You can purchase replacement caps for your fuel jug, and just plug the vent line to close it off when the jug is not in use.


Brad

KitBuilder

I just keep and eye on the muffler pressure line and stop pumping when I see it...before it even gets to the muffler. Why do you disconnect and let it pump out the line to start with?
Mike

danny31292

I use a dave brown pump and I can tell before it starts to over flow. Otherwise I would use an over flow bottle. And as others said I hope your asking these questions so you know what youre doing before you even meet an instructor. Even then it would be best just to let him show you everything.

DTOWE

I have several planes that the engine is complety enclosed in the cowl. You can't get to the fuel line on the exhaust or the carb line without removing the cowling. I drill two holes in the engine cowl and run the carb line from the tank thru the drilled holes and back down to the carb. I have a third line from the tank that I fuel the plane with. When i am filling the tank I watck the fuel line to the carb thru the drilled holes in the cowling. I admitt I do loose a little fuel when fueling. But not enough for me to try to recapture.

Semi Retired Aviator

Dr 1 Driver, you're right...this isn't rocket science. I do it this way.

I use a hand crank pump and the first time I fill (assuming I can't disconnect the pressure line to see fuel coming out), I listen for the 'gurgling' in the muffler. That's a sure sign it's getting close.

I also count the number of turns of the pump to fill each tank I have, and as I approach that number of turns I slow the rate of pumping.

This has a secondary benefit; when I fill a partially empty tank after a flight, I know how much I've used on the flight, e.g., 13 turns to fill a tank that took 40 turns to fill from empty is about a third of the tank burnt. Using this method, I wouldn't waste a teaspoon of fuel from a gallon.

I find that the simpler the method the less chance of mistakes, and it doesn't get any simpler than this with a cowled engine. Of course, ifyou can disconnect both lines, that's pretty simple too.

Avalanche2

Hey Panzer, just remember.. there are no stupid questions.. ask away... nobody is born knowing this stuff... When I got started I made sure to support my LHS even if it cost a little more than the net. stores... these guys are a wealth of info. and most are club mentors to boot.. now they are friends....

scratchonly

If you're using an electric pump the motor changes tone when it stops pumping air thru the over flow and starts pumping fuel because it is working harder; keep your hand on the switch and turn off when this sound changes. Works for me.