RE: Draining fuel and running the engine until it quits
 

I see tower hobbies has it for $90/4gallons which is alot more, so it sounds like fuel is one of those things best purchased locally.

RE: Draining fuel and running the engine until it quits
 

Has anyone any experience with Wild Cat glow fuel? It sounds like another premium fuel but you can't believe the ads I guess.

http://www.wildcatfuels.com/fuel_premium.htm

RE: Draining fuel and running the engine until it quits
 

I run Wildcat in both my planes and cars, its good stuff. The pricetag is right too, for now.

RE: Draining fuel and running the engine until it quits
 

I have used the following brands and all have performed very well: Cool Power, Magnum, Omega, Powermaster, Ritch's Brew, Wildcat.

People in our club also use Sig and Byron's fuels with good results.

As long as the oil type and percentage are correct for your engines (see the manual), I think the majority of fuels are very good.

RE: Draining fuel and running the engine until it quits
 

Definitely buy fuel locally if you can. If you have it shipped, you have to add a "hazardous materials" shipping fee on top of the price.

RE: Draining fuel and running the engine until it quits
 

That's the free market society. They can set their price at whatever they want to. But at $30/gallon they are asking for and getting over 100% profit over thier cost. If everybody there didn't pay that price they would be forced to lower it.

Ken

RE: Draining fuel and running the engine until it quits
 

Does anyone know what percentage of Nitromethane CoolPower has?

RE: Draining fuel and running the engine until it quits
 

I realize that most people answered that they reuse the fuel pumped out and that's what I plan on doing as well, but I just checked Morgan Fuel Cool Power FAQ and it states:

Q: "Should I pour the unused fuel from my tank back into the fuel jug?

A: No!

As mentioned in the question above about shelf life:

A quick way to ruin a gallon of fuel is to drain your tank at the end of your flying day back into the fuel jug. What is happening is that your fuel is picking up moisture from the pressurized tank. The carburetor is sucking in humid air and after combustion the moisture laden air is entering into your tank via the tube from your muffler. When you return the fuel from your tank to your fuel jug you are contaminating the rest of the fuel in the jug.

My recommendation is to run your tank dry at the end of the day, but whether you do that or not don't return the fuel from your tank to your fuel jug. "

Of course to me and sounds like most people that's not practical and of course the manufacturer would like you to use as much of their fuel as possible.

Bottom line, I have come to the conclusion the best real world solution is to try and fly until almost all the fuel is used (or to practice dead stick landings, until ALL the fuel is used) and then pump any remaining fuel, which should be a minimum amount, back into the jug.

RE: Draining fuel and running the engine until it quits
 

There's a very good reason why you should run the engine dry at the end of each day's flying. Methanol soaks up water from the air like a sponge and water causes rust. I think everyone knows you can pinch the fuel line, or even remove it, when the engine is at idle and it'll keep running for several seconds. That's because at idle the crankcase fills up a little with raw fuel because there's not enough air flow (turbulence) inside the crankcase to sweep it up into the cylinder. To get rid of this excess fuel you should run the engine at high speed, even full throttle, then pinch or remove the fuel line. The engine will stop almost straight away but as it runs down to a stop it's still sweeping up tiny bits of fuel that aren't enough to actually burn so they get swept out the exhaust. Now all that's left inside the engine is oil.

So, after run oils. Synthetic oils as used in fuels tend to slide off metal surfaces like water off a duck's back leaving the metal exposed to air which will have some moisture in it. Once again, rusting. After run oils are different to synthetics because they have a special property that makes them like to stick to metal so air (and moisture) can't get to the metal. No rusting. But most after run oils won't mix with methanol so they can't be added into the fuel to make sure it's covering every part inside the engine. Except for one extremely good after run oil. Castor :). It also happens to be an exceptionally good lubricant so you get the best of both worlds.

And one hint. If you run the engine dry at full throttle by pinching the fuel line then keep it pinched for a few seconds after the engine has stopped. This gives time for the pressure that's built up in the nearly empty tank to drain back through the muffler. If you let the line go as soon as the engine stops then the pressure in the tank will force some unwanted fuel back into the carb.

RE: Draining fuel and running the engine until it quits
 

Thats actually an exageration, it only soaks up water it comes in contact with. If you put humid air in a jug of methanol it will eventually asorb the water, but it takes time. Morgans has a point about the fuel getting contaminated from the pressure tap line, but they were wrong about the moist air, even with 100% dry air the combustion of alcohol will produce lots of H2O vapor. It can be a problem if you were to say only fly a few minutes a day and pump back a nearly full tank back in the fuel jug for each short flight. But I have no problem with normal usage.

RE: Draining fuel and running the engine until it quits
 

Running a 4 stroke dry does little good in so far as keeping it from corroding. A four stroke will always have a fair amount of fuel and exhaust residue in the crankcase, even if run dry. That is why, IMHO, on fourstrokes, use after run oil and put it into the crankcase. Putting it in the exhaust or carb will do little if any good as it will not get to the main bearings where the rust problems will usually start. Not just a drop or two but about a teaspoon full then manually rotate the prop and engine to make sure the oil gets to all the bearings to displace any fuel. As mentioned above, it is the nirto component in the fuel and oxygen that will do most of the corrosion problems so coat the bearings with after run oil to displace the nitro laden fuel residue.

RE: Draining fuel and running the engine until it quits
 

But likely not totally empty. I am very religious about pulling the fuel line off the carb, priming the engine and hitting it with the starter again - several times. In fact, I have a small quantity of castor-only fuel I use to do this.

If you simply shut off the engine using the throttle, there will surely be a bit of raw fuel in the crankcase. Not good for the steel crank or ball bearings - especially if you use an all-synthetic lube.

Be careful though... Once I pulled the fuel line off and restarted the engine. There was still about 1/4 tank of fuel and the muffler pressure line was still hooked up. I couldn't figure out why my engine kept running and running and running - and throwing fuel everywhere. The pressurized tank was spraying fuel out the disconnected fuel line and some of it was getting sucked directly back into the carb across a 1" gap of open air.

An after-run oil is also helpful, no matter what the various fuel manufacturers will tell you. You can make up an effective home brew after-run concoction using 50/50 automatic transmission fluid and lighter fluid. The engine will fire on this mixture and the ATF gets distrubuted all through the innards of the engine. In fact, that expensive commercial after-run oil you use may be exactly the same thing you can make yourself.

RE: Draining fuel and running the engine until it quits
 

Disagree. I don't think nitro is corrosive. The methanol we use will absorb water out of the air. The water is what causes the corrosion. You want to get the methanol out of the engine and coat it with a protective film of castor oil.

RE: Draining fuel and running the engine until it quits
 

Cappa, I read on one of the engine mfg. sites that they mean do not inject the afterrun oil directly into the fuel access at the needle valve. That assembly must have some o-rings. Through the carb is the accepted approach. They also said a few drops will do nothing to protect the engine, they recommend at least a teaspoon.

RE: Draining fuel and running the engine until it quits
 

You are right. It is filled with air. But not a drop of useable fuel.

For those of you running the engine dry on the ground, do it then wait for a minute. Then hook up the glow plug and spin the engine again. Quite often they will fire again with the fuel that is still in the engine.

RE: Draining fuel and running the engine until it quits
 

Rust in an engine is almost totally an RC related problem because it's vitually unknown in CL flying for two reasons. First, they (we :)) nearly all use castor, either straight or a blend. Second, the engine always runs out of fuel at full speed because it's the only way to land :D.

There's a lesson to be learned there somewhere.

RE: Draining fuel and running the engine until it quits
 

Yep, run it dry, then keep trying to start with glow driver and starter until it is TOTALLY dead; the prop should spin as if the plane were sitting on your shelf for days, no extra help. I close my throttle to the idle position afterwards, and fill the carb with after run. Then I spin the prop which sucks in the oil, and turn the prop about 7 times to coat everything in there.

RE: Draining fuel and running the engine until it quits
 

The reason is that the part of the nitro residue is converted to nitric acid by reaction with the atmosphere. It is the nitric acid that does the damage.

RE: Draining fuel and running the engine until it quits
 

Regarding getting gunk in your fuel that you then pump back into your fuel container when emptying your tank, I put a fuel filter between my muffler pressure fitting and my fuel tank. That way the gunk produced by the emissions doesn't get into the tank.

RE: Draining fuel and running the engine until it quits
 

I just read an engine clinic article in one of the mags that suggested using as much as a teaspoon of afterun oil.
The same author also stated the claims made by synthetic blend fuel manufacturers that after run oil isn't needed when running thier product is over stated and optimum maintenance does include afterrun oil.

After watching this debate for years, I realize there are many opinions and many claims. Ulitmately the consumer must decide wether the data from the afterrun oil company, the data from the synthetic blend company, or your own experience in the field is the most valid.

With a fleet of airplanes to choose from, and an erratic schedule that might inadvertantly cause an engine to sit unrun for weeks or even months, I choose to error on the side of caution and follow the advise of the magazine article. However, someone with only one airplane, and with a schedule that virtually assures the engine will run again very soon , can certainly get by with a lower level of maintenance. I don't believe there is one absolute answer that is correct for everyone. In fact, in years past, I ran synthetic blends, flew almost daily, and never ran and engine dry or used afterrun oil. I had no problems. That same regiment, in my opinion, no longer fits my situation.

RE: Draining fuel and running the engine until it quits
 

I've changed my thinking after having so many deadstick landings recently and thinking it contaminated re-pumped fuel could have been a contributor. I tend to fly short flights, and usually have a lot of fuel left in the tank at the end of the day and have been pumping it back to the jug afterwards. I still have my initial gallon of fuel so I haven't been flying that long but out of about ten solo flights, the majority of them have ended in deadstick landings after the engine quits. We've pulled the carb, cleaned the inside parts off, made adjustments to the low and high speed needles and changed the tank and all the fuel lines. None of that worked. Today, I had two flights without a deadstick after removing the baffle in the muffler and switching back to my old tank and lines plus adjusting the high speed needle so I'm running a little on the lean side. So far so good. I think the re-pumped fuel is adding moisture from the pressurized tank and that wasn't helping the problem.

My thinking now is to leave whatever fuel is left in the tank at the end of the day, and to just try and fly the airplane close to empty on the last flight of the day.

Then, after disconnecting the fuel lines from the carb and muffler, run any remaining fuel in the engine out by starting the engine and running it until it dies.

Last, afterwards, squirt some after run oil in the carb, and turn the engine over several times by hand to lubricate the engine thoroughly.

That's going to be my routine from now on.

RE: Draining fuel and running the engine until it quits
 

RE: Draining fuel and running the engine until it quits
 

Hummm think I did the quote thing wrong. Look next to last paragraph on your quote for my reply

RE: Draining fuel and running the engine until it quits
 

I'm not saying that's what caused the problem but I do think it was contributing. When I removed the baffle from the muffler I noticed alot of ugly looking blackish fuel inside. That stuff is getting back into the tank when I pump it out each time. It can't be good. Morgan Fuel states 'The carburetor is sucking in humid air and after combustion the moisture laden air is entering into your tank via the tube from your muffler.'

I'm just going to not pump it back from now on as a precautionary measure and to feel a little better. Probably not causing the problem but you never know.:)

RE: Draining fuel and running the engine until it quits
 

You're probably right. I doubt its causing you greif to reuse the fuel. I am new, but EVERY flier I know pumps it back into the jug and reuses it. I have personally used a leftover jug from my first venture that had roughly a quart and a half left in it from 5+ years earlier, that had been run like described putting the leftover back in the jug. I had no issues, at all. At nearly $20 a gallon I see no reason to waste fuel that is probably good just because one or two people have had problems, especially with so many who do not.

I do however religeously use after run oil even though my fuel says I dont need to..

I suspect your dead sticks are caused by something else, tuning, air in the fuel line or other.. I had a stream of them, no more than 5. I had a veteran flier help me retune and they went away.