Capflyboy05

How do I know what kind of fuel to use?
Percentage wise I mean.
My friend/instructor always just gave me the fuel...
Maybe he told me, I just dont remember.
I have many planes, but I'm not sure what engines take what.

Campgems

If you list your engines, you will get a more meaningful response. I'll say this, I use 15% nitro with castor/synthetic mix in just about everything I fly. I fly mostly 4 strokes, from 52 through 180s and a couple Thunder tiger 40 two strokes. One jug works on all. I know that some engines like a lesser amount of nitro, I have an older Tartan twin 47cc that wants no nitro and a low oil content, IE mix my own. Four strokes idle better on the 15% nitro. Some Saitos like 20%. So, a list of what you have will get you answers for your engines..

Don

vpresley

My Feedback: (162)

Hi

If they are newer ball bearing Glo Engines, use a good name brand 10% nitro fuel as a starting point.


Vince

Capflyboy05

The one I am most interested in running right now is an Enya 45.
And around that size.
I'll have to check tomorrow on all of them.
I have multiple sizes.
VERY old engine.
But I inherited all of these engines.
They all ran well 3 years ago.
I just want to put the right fuel in so I dont ruin anything.

bigdanusa

A friend of mine in our club had a super tigre .45 using 15% fuel and it kept dead sticking on him until he used some 10% in it.

I personally use 10% wildcat 2+4 stroke total synthetic fuel and seems to work fine in my engines from .40 2 stroke engines up to my .91 surpass 4 stroke. I found using total synthetic oil compared to castor mix oils, my engines don't get all gummed up and don't leave burn marks on the outside of them.

big dan

mike109

G'day

Hmmm, Which Enya 45? Some have AAC setups (Aluminium Liner, Aluminium Piston and liner is Chromed) the CX-45 is like this and I have one of them but some of the older ones used iron pistons with steel liners and they need castor. Some are plain bearing and they need castor too.

Do you have a photo? It would help to identify the engine and so its preferred diet.

In general, ABC and AAC engines with ball bearing crank shafts are fine with synthetic oil but the older iron/steel engines need castor and especially if they are plain bearing (bushed) engines.

MinnFlyer

My Feedback: (4)

If all you have are 2-stroke engines, I would use 5 - 10% nitro. If you run 4-strokes, I would bump that up to 15%

ameyam

Capflyboy05,

to add to what everyone has replied, if you are simply running the Enya 45 .46 size 2-stroke ABC glow engine and you dont want to spend too much, you can simply even run plain castor fuel (18-20% castor and remaining methanol).

Nitro is an oxidiser- it provides oxygen for combustion when there isint enough taken in by the engine. It simply means that adding 5-10% nitro to 2C fuel makes the idle more reliable. But for your size engine its may not be necessary

Now regarding synthetic- it gives a cleaner running engine with less "gunk". But since synthetic lubricant has a low flash point, it will burn off easier. Meaning if you run too lean there is possibility of wear. For this reason, most dont suggest plain synthetic, but instead a mix of synthetic and castor. But you can run plain castor, I did for several years on a 55AX

For 4 cycle engines, there being more moving parts, plain castor or plain synthetic is undesirable. Most use a lubricant with a blend of the two e.g. I use Klotz-100 which has a 80-20 synthetic-castor blend in the lubricant and I use 20% lubricant in the fuel. Also, for 4-stroke engines, since the power is produced every alternate stroke, some nitro in the fuel ensures the engine does not cut at idle, so I use 10% nitro.

For the sake of simplicity, I use the same fuel in both 2C and 4C engines.

It is really quite simple after you understand why each component is required. Hope I didnt give any wrong advice, please correct if I did

Ameyam

Gray Beard

My Feedback: (-1)

+1. I When I was flying smaller planes I was also flying with bigger planes too so I got into the habit of using nothing but 15%, it works in everything. I have also done a lot of testing and 5% and 10% are just dandy for the smaller engines.

ron ward

  just a question out of curiosity...
           when did all this differentiation about fuels start?  i flew large u-control and some r/c 40-some years ago and there was never any question about fuels....at least not in my group of flyers, we all used Duke's and/or some other commonly found fuel that i can't recall the name of, but as far as i recall,it was all basicly the same. 
          now 40 yrs. later i am learning that there's big differences in fuels.......i am close to the point of breaking in my first engine since then and want to do it right.

MinnFlyer

My Feedback: (4)

Engines have come a long way since those days

speedracerntrixie

My Feedback: (29)

So very true. The rule of thumb that I use on selecting fuel has more to do with where the engine was manufactured. The asian manufactured engines all respond well to higher nitro fuels 15%-25%. The Saito and YS 4 strokes work well with up to 30% nitro. The Europian engines are set up to run lower nitro 0%-10%. Most of this has to do with the compession ratio. For most of your asian built 2 strokes 15% nitro with 20% oil will work just fine. IMO anything made in the past 20 years will work well with strait sythetic oils and have no need for castor. Although some believe that castor lubricates better it also increases carbon build up and will gum up an engine that does not run on a regular basis.

bigdanusa

A guy in our club uses 10% "club fuel" that he's had for 30 years in all of his engines.

He's a Pilot for United Airlines that flys the L.A. to Hong Kong route so he can't be too stupid!

His motto is: If it works, why not use it!

I might give him a gallon of my Wildcat 10% 2+4 stroke fuel but i'd hate to see him dump out all of his remaining 30 year old fuel after trying "my" fuel out!

big dan

speedracerntrixie

My Feedback: (29)

Thats funny, I know a corporate pilot that always goes cheap with his models too. I only run glow fuel on my pylon airplanes but my rule of thumb is whatever I havent used in 2 months gets used as weed killer

Gray Beard

My Feedback: (-1)

So has fuel. With the anti foaming agents they put in it there is no foaming at all. Nitro content is a mater of choice and how well you can tune an engine. My YS engines ran with 5% but required a tune job to run well with it. They were just fine with 10% but I have been using 15% for so long I have never bothered to change. Ont fuel to do it all!! FAI fuel is just alcohol and 20% castor oil across the pond. Here the oil is often a blend but still called FAI. If you can tune an engine they will all run the FAI, some just better then others. Oil content is the main issue, most fuels have between 18% and 20%, I have run into it as low as 15% so I add oil to bump it up. Fuel doesn't go bad with age if stored correctly, wish I lived closer to speed, I would trade real weed killer for his old fuel. Engines come with instructions or you can find them on the net, they tell you the fuel type the manfacture wants you to use.

Jim Thomerson

I've been flying Sig Champion 10% Nitro, 20% oil, half castor, half synthetic, for many years. I run it in TD 09, McCoy Red head 19, Fox stunt 35, K&B 4011, and Tower 40. A mix of iron and steel, ringed, and ABC engines. It works fine. I am presently flying fuel that is four years old.

speedracerntrixie

My Feedback: (29)

LOL Gary, I suppose we will have to dis-agree on this. The good news for you is I have a half gallon of Byron 15% with your name on it. Glow fuel is alcohol based and once the seal has been opened, it startsabsorbing moisture. You can slow the process but never really stop it and yes todays fuels are better at even this but it still happens. On my race planes I notice a drop in RPMs if the fuel is a few weeks old. When I flew helicopters, the engines ran noticably hotter when the fuel was more than a month old. I even noticed that engine bearings and crankshafts would rust faster. So I will continue to remove my engines after a weekend of racing, lube them up with ATF and bag them and I will save all my old fuel for ya. Maybe meet up in Vegas one day and give ya a case or two of half empty jugs

Gray Beard

My Feedback: (-1)

I'm game and would be very thankful. I have burnt fuel that was opened 15 years ago, everything from 5 to 20%. Stored in a closed cabnet out of the light. No problems with it at all. It was stored in the central valley too. Bring it with you next trip to fun land!!
Gene

downunder

I'll take a guess that your Enya has either model 6001 or 6002 cast on the side of it. If so then they're quite old, baffled piston with rings and are very good engines. I've only ever run mine with 20-25% all castor and no nitro but I mix my own fuel so you won't find anything like that at the LHS. It'll run fine with some nitro but the oil content might be a bit of a problem because most fuels lately are somewhat lacking in oil, especially castor.

Nitro is an American phenomenon, mainly because nitro is cheap there and it'll give a boost in power, but the truth is that all 2 stroke engines will run perfectly well with zero nitro. 4 strokes will also run on zero nitro but they're designed with very low compression so they can use high nitro fuels to boost their power to come closer to matching the power of a similar sized 2 stroke.

If your other engines are similar to the Enya (ringed with steel liner or even ABC) then the fuel Jim Thomerson mentioned would be fine but if any have a cast iron piston then you're going to need 25% all castor. A list of your engines would help though.

Capflyboy05

List of engines. (Bear with me,)
I didnt feel like taking the cowling off the FW 190. So thats the only one missing.

Super Tigre MDS 40 (The one I would like on my Avistar)

Max OS 25 (Not mounted)

Super Tigre 15 (Not mounted)

ASP ??? (Mounted on Zero)

Max OS BX1 (Mounted on EAA Biplane)

Super Tigre 51 (Mounted on Ugly Stick 1)

OS FS 61 (Mounted on Ugly Stick 2)

Magnum XL 120 (Not mounted)

Enya 45 model 6001 (Mounted on Custom Built Trainer)

Enya 35 model 5224 (Not mounted)


So theres the list.
Theres still a few more laying around in boxes.
But I think you all get the point.

(I inherited all of this stuff)
Thats how I got so much so fast.

Prop_Washer2

My Feedback: (26)

Hmm..never seen a Super Tigre MDS? I've seen Super Tigres', and MDS's as I own both. MDS' are a low nitro fuel motor, and STs' are pretty flexible on Nitro depending on model. And yes fuel doesn't go bad if sealed and stored properly. 20 year old fuel can be as good as new, now where is that guy with his free "weed killer"..??

But what do I know, I just work for NASA and inspect and buy fuels for DoD...

Prop_Washer2

My Feedback: (26)

Hmm..never seen a Super Tigre MDS? I've seen Super Tigres', and MDS's as I own both. MDS' are a low nitro fuel motor, and STs' are pretty flexible on Nitro depending on model. And yes fuel doesn't go bad if sealed and stored properly. 20 year old fuel can be as good as new, now where is that guy with his free "weed killer"..??

I would just use 5 to 10% Nitro, with a Synthetic/Castor based oil content like Morgan's Omega...

But what do I know, I just work for NASA and inspect and buy fuels for DoD...
[quote]ORIGINAL:

Capflyboy05

Thats what I was thinking about using... 10%
Sounds like a decent job my friend!

CGRetired

My Feedback: (1)

Just about everyone at our field uses S&W 15% nitro fuel with 20% oil blend on just about everything but the gasoline powered planes and recommend it to anyone that asks.

Even the pattern folks, who are probably the most fussy when it comes to what they use in their engines recommend that fuel. We buy that fuel in bulk. Reason being that we lost all of our hobby shops, with the closest one about 50 or so miles away and his selection is limited and high priced. Mail order is out of the question.

So, we buy in bulk by going to S&W at the beginning of the season with a large order.

I have two cases left from last year, and my field jug is half filled from what I didn't use this past season. It's sealed by the screw-top and in a cool place in the house, right next to the two cases of "fresh fuel". It's just fine.

CGr.

goirish

we just ordered another drum of 15% full synthetic from S&W again this year.