XJet

I've tried everything from 0% to 10% with little difference observable.

This depends very much on the quality of your oil :-)

We regularly run Cooper's Liquifire Plus-C oil at ratios of 12%-14% by volume and have had nothing but great success without a single sign of engine wear, even after many gallons. In fact, dropping the oil percentage has had more effect in improving the ST90's mid-range performance than any other single factor.

And yes, I've tried older-formula oils such as CoolPower and straight castor at 18%-20% by volume -- that produced the poorest results of all.

TCrafty

I was also very skeptical about buying a SuperTigre 2300 after seeing all the posts about them. I've had good luck with my Saito and OS engines but decided to try a ST anyway. I put 5/32" fuel line to the tank and a 17X8 APC prop on the front of it. I put about 3 tanks of fuel through it before flying it and took it up for about 3-4 10-minute flights. As the engine was breaking-in, I noticed that the high end was a tad lean and the low end was a tad rich. I plugged the one exhaust tube closest to the pressure nipple on the Bisson muffler, which solved the high end's lean condition without touching the needle. I then leaned out the low end about 3/4 of a turn. Now it runs great, idles forever and transitions seamlessly. I, for one, would definitely consider another ST. Maybe I got a fluke engine that works but so far...

By the way, I've still got the original carb on it too but did go with a Type-F plug.

rc34074

My Feedback: (5)

tcrafty - smart diagnosis. I do pretty much the same thing and my 2300s run great also.. much cheaper and easier than changing carbs etc. the osf plug is what I usually go to after its fully broken in. during breakin I use the fox rc long plug.

Ed

TCrafty

So I can only expect it to get better as it breaks-in more?

NM2K

My Feedback: (14)

I'm not doubting what you say, but the ST engines are suffering from carburetion problems, not too much oil. Glad your fix is working for you and not damaging your engines.

Many folks don't realize that our sacred cows (18 - 20% oil) are just proven compromises. If one is very careful about never getting off the ground lean, not over propping, etc., one can get away with much less oil than the sacred cow indicates. We don't even take viscosity and many other factors into consideration simply because there is no information readily available to educate us. Better safe than sorry has been my motto for many years, so I'm guilty of running more oil than I truly need. Unfortunately, oil is the most expensive component in the average modeler's fuel jug, when amount and price per unit are co factored.

Now, if they would sell that European miracle oil (it is a miracle to me) at normal prices, I think you would see a stampede in that direction from those in the USA.

ST better get their act together before they run out of customers. The paradigm has changed regarding what is considered adequate carburetion. Folks aren't up to fussing with a fussy carburetor when other engines are available at similar prices and performance that do not need all of the head scratching that is required by the Super Tigre engines in the larger sizes. Whether the "experts" keep expounding about how wonderful the ST carbs are or not is not relevant any longer.


Ed Cregger

rambler53

My Feedback: (494)

It would have been far more pleasant to read you helped your fellow flier break in his engine and tune it for him than sack him for your own gain.

Trollmaster

Well there are those of us who can tune an engine like a swiss watch because we pay attention and there are those couldn't tune a fork! Whatever the heck that's suppose to mean but sounds negative to me, so I wrote it in

rambler53

My Feedback: (494)

At least you're not calling people names yet, RCU forums have worse threads...

Hobbsy

My Feedback: (102)

It's all in having a gentle wrist, small changes are required to find the sweet spot.

NM2K

My Feedback: (14)

---------------


While I've never been rich, I've been fortunate to have been in a position to buy pretty much what I have wanted in the hobby. Fortunately, my needs/wants have been modest by most standards.

The idea of letting a fellow modeler get discouraged and throw away good equipment is very distasteful to me, as is what you implied in your post.

Of course, I attempted to help the unwitting and impatient Fox owners break-in their engines properly. Sometimes I actually succeeded, but quite often my offers of help were rejected. Those whose engines did not satisfy their owners' demand for instant gratification, quite often won't listen to someone telling them "the truth" about their engine and its specific needs (castor oil).

Ed Cregger

rambler53

My Feedback: (494)

Oh the denial. I didn't imply a thing, Ed. I quoted your words exactly as it appears in this post. You bragged you owned their engines eventually, and they were pissed you got it running good for yourself, and why were they pissed? Elaborating or backpeddling now was expected, but why is it so hard to say you were wrong? Glad you say you tried to help and yes, some refuse to be led to a pool of water, just as you refuse to see it was offensive to read your post that didn't say a thing about being turned away with good intentions up front until now.

Fox carbs are nothing like Super Tigre carbs either, so let's get back to the subject. (reading your market buys here, you selected Enya, OS, and K&B....hmmmm. )

avatar14

I have a G-90/Bisson Pitts in a GWS P-51, running a 31x6 with 15% nitro/18%caster. My first two flights ended with that midrange deadstick. After reading through all these articles about new carbs, fuel types, plug types and muffler mods I almost took the engine out to play soccer with. I have found that if you take the time (took all of 1/2 tank of gas)to set the idle by pinch testing it and then adjusting the high speed needle it now transitions smoothly. Oh yeah, I forgot to mention that is exactly what the manual tells you to do. I've only been in the hobbie for 2 years so I'm still learning. I would agree that it takes a little more to break in than others but it is one tough motor and has my plane screaming.

Trollmaster

A 31/6?

Trollmaster

I assume you mean 13/6. My G90's have been runing great for several years.

Ernie Misner

My G90 still wants to start sputtering if you let it idle for more than 15 seconds. It's been adjusted very carefully by all the local experts for over 2 years now...... any more ideas. Oh, and it's had 3 different carbs on it too.

Thanks,

Ernie

Flyer95

My Feedback: (1)

Try remove the headgasket and use a OS-F glowplug as it helps a whole lot for better idle.

Ernie Misner

Do you mean run no head gasket at all? Will the head make a good seal that way?

Thanks, Ernie

Flyer95

My Feedback: (1)

Yes, I run mine that way all the time and use 10% nitro in the fuel and OS-F glow plug seems to work best.

Ernie Misner

Interesting! Have you ever seen a G90 that wants to sputter and cough when it idles?

Flyer95

My Feedback: (1)

Mine did not like the common twostroke glowplugs as the idle would be rough and unreliable. It runs a whole lot better with the fourstroke plug OS-F.
Been using this plugs for many years now on my Tigres and I am pretty sure it is the best one I have ever tried.