Hey,

I have a question which fuel I should use in my OS 46 FX and Magnum xls 61.

Thanks

Select a fuel that has 10% or 15% nitromethane, with an oil content of at least 18%.

FILE IFR,

Thats what I told one guy at the hobby shop but he told me to get the Omega 10%, as far as I know omega has 17%of oil.I told him that in the OS manual it says that there should be 18% but he didn't believe me....

Will 1 gallon of the Omega fuel damage my engine???


P.S....I like your username..."File IFR"..Flying IFR is as much fun as flying the RC airplanes

You'll be fine running on 17% oil from now til eternity. While it would be nice to have that other 1% it also depends on the oil type. http://www.morganfuel.com/omega_blends.htm read up on Omega fuel and you will see they use special synthetics. Don't worry, you'll be fine.

Omega uses castor, which is why there is a slightly lower percentage in the mix. The end result is about the same, though castor acts to protect the engine at higher temps due to the varnish it leaves behind.

The OS runs great on 10% nitro. I have no experience with the other engine but it should also work well - no need to spend the extra money unless you are competing.

I don't use fuel with 17% oil. Some fuel manufacturers say it's OK, but the OS manual says at least 18% meaning more is ok but not less. They have great service and warranty coverage, so why not listen to them?

No trouble with the Omega fuels, just A different blend. You could even give the 5% nitro A try, as long as the engines idle OK then it makes no difference. This time of year it could be A bit of A problem though, my engines aren't liking the cold morning starts and I'm using 15%. Can't get at the carbs to give them A shot of lighter fluid either.

I've been running 15 % Omega for years..2 strokes 4 strokes OS Saito....never have had a problem....IMHO....whatever you're running 10 15%whatever, pretty much stay with the brand and nitro content consistantly...if you switch every gallon then your going to be re-tuning the engine alot....now it doesn't mean you can't switch content and brands...you will probably have to re-tune that's all...

Are you entirely sure about that? Do you mean percentage by volume or percentage by weight? Does OS mean by volume or weight? And are you sure about the percentage that your manuals state?

For the 46AX, Hobbico says 16%. For others, they list up to 20%.

Omega will work fine. I've used it for years, along with Morgan's Cool Power. I've also used Sig Champion and Wildcat, and probably a few other brands, too. The common blends from the large manufacturers will all be just fine. What you have to watch out for are the blends from the fellow who buys ingredients in bulk and blends his own.

Use what ever you can get pretty handy. It was nice for me cause coolpower is everywhere around here. so it worked out nice

I have been running all summer with the omega 10% and I am using it in everything. Enya 80XF with tuned pipe, saito's, etc. I do try and run on the rich side, and have not had a problem. I have been using a tach. to adj. it seems to help get a good slightly rich setting.

sticks

I'll take 17% oil and a slightly rich fuel/air mixture to 20% oil fuel that's needled too lean any day.

If your engine leans out and loses power in mid flight, close the throttle and land! If you don't throttle down, you're going to dead stick anyway. If you do throttle down, the engine will often keep running instead of dying and you will be able to come around and land.

In my OS engines I always run what the manufacturer recommends... why mess with a good thing. I run either 10 or 15% nitro and 18% oil with the oil breakdown to be 80% synthetic and 20% Racing Castor. Wildcat fuels does the trick for me... Now if you really fly a lot and go through some fuel you may want to look into mixing your own, it is cheaper.

Go to the fuel forum here... there is lots of good info on fuels, mixing your own, what more or less nitro does for you... etc....
http://www.rcuniverse.com/forum/forumid_161/tt.htm

You won't have a problem with the Omega, I primarily only use Omega because that is what I get a deal on through the club.
I have never had a problem with it and never hesitated using it on any of my brand new OS engines.

As costly as O.S. engines are, I don't run anything with less than 18% oil in mine. You can always add some castor to bring the ratio up to the correct percentage.

I think I will use whatever I bought and then will switch to Wildcat 15% and stay with it from now on...

For 1 Gallon of fuel, how much oil should be added in order to get the rate ratio.
How expensive is the cartol oil and where can I buy it?

If you get the caster by the gallon, its not too bad. I did the math and if you buy it localy in small amounts its about $80 a gal. My friend and I ordered two gallons and got it for around $30 a gal. with shipping.

If anyone knows cheaper, let me know......

sticks

$80 a gallon....I think I will just use whatever fuel I have and then buy Wildcat 15%.

Can somebody explain to me the difference between 10% vs 15% nitro?

Not alot.
15% will give slightly better performance but just slightly better.
I found that my 4 stroke engines seem to run better and cooler on 15% so just to avoid buying a bunch of different fuels I use 15% for everything even though my 2 strokes seem to run just as well on either one.

Important to note that Wildcat EXTRA has 18% oil; if it doesn't say EXTRA on the side of the label, vertically, then it only has 16%.

I buy bottles of castor from Price Chopper; $2.75 for 6oz, and a half bottle to a gallon will bring the oil content up over the 1% you need.

Wildcat Extra 10% is a great fuel - enough power, enough oil, and less expensive than 15%. The only thing I noticed about using 15% nitro is how much faster I burned fuel (have to open needle valve to let more fuel in).

I pretty much do what MM does and just buy one fuel, in my case I use Power Master 15%. It is the number one fuel in my area, comes up on sale A lot so it's around 15 bucks A gallon and I stock pile it when I have the money. In Calif. we had club members buying pallets of the stuff and we would get A great deal on cases. Nitro content is mostly to to help with the idle of the engine and you will get A power boost as more is used. No reason to say any more about it, the hows and whys of it all. If you want you can do A search on nitro and read for weeks what everyone has to say about it. If you go to Europe and fly it's either going to be hard to find any nitro fuel or cost way too much. FAI fuel is just the alcohol and Castor blended and used as fuel in most countrys besides the US. If you want to use 5% it isn't hard to tune for it and it works quite well for sport flying. If you can, borrow A tank of different percents from club members and see what happens, you will find A surprise or two.