Mid-range problems on SuperTigre

[Roman Sochan]

I have a SuperTigre GS-40 ringed engine that is about a year old.
It runs fine at full throttle and at idle, but the mid range sounds
terrible, and the transition through the mid range is rough.

Any suggestions?

[Learjet35x]

Sounds like you might be sucking in air aft of the carburator.... I just had
same problem on my Saito 150... it was missing the O-Ring between the carb &
the intake manifold...

LearJ...@NO-SPAMaol.com

<remove NO-SPAM from email address to respond>

[Wayne Armstrong]

Sure but more info would help as in;

What type of fuel are you using?
What type of Glow Plug?
What prop size?

The first thing to know about Supertiger engines is that they are designed
to run on 0% Nitro. If your running anything over 5% Nitro you need to add
an additional head gasket. They also run well on K&B idlebar plugs.

Wayne

Roman Sochan <rso...@removethis.ix.netcom.com> wrote in message
news:7i49k1$6...@dfw-ixnews6.ix.netcom.com...

[John Smith]

Now, my boy! here is one of the great things about the ST carbs
----adjustable midrange!!

The fuel spray bar in the carb throat can be adjusted by rotating it
slightly to richen or lean the midrange. By turning it a little, the
fuel draw changes (over the entire throttle range), thereby changing the
mixture. Loosen the two small screws (these hold in the spray bar
fitting --- the fuel nipple is attached to it), and rotate a little
(from .000001 degree to ~5 degrees). Run the engine, and re-adjust if
necessary. This is a limited adjustment, but it will do what you need.
As I said, it changes over the entire range, so the low and hi needles
will have to be re-adjusted.

Do not forget to get a fresh glow plug (OS8 or Enya 3 or 4 recommended),
check your fuel for freshness, and do the other things that are pretty
basic to troubleshooting.

The ST GS-40 is a fantastic engine. Mine really hauls the Kadet Senior
around with great authority. I continue to be impressed with it every
time I start it up.

Good luck,
Bradley

[BROCKKM]

THIS IS A BUNCH OF HOGWASH I FLY NOTHING BUT SUPERTIGRE'S I RUN THEM ON 15% AND
10% NITRO USING A O.S.A3 NON-IDLE BAR PLUG
PERFORMS EXCELENT

[BROCKKM]

WAYNE WAKE UP! IF YOU GIVE ADVICE AT LEAST SAY SOMETHING TRUTHFUL AND NOT JUST
BLOWING IT OUT OF YOUR BUTT

[Brad J.]

In article <19990531024603...@ng-cg1.aol.com>,

I don't think the original question was " Can you prove your a horse's
ass in twenty five words or less?" Did your response help determine a
fix to the problem?

An open minded individual with the ability to think for themselves can
learn from what works for other people and thier experiences. There is
often more than one solution to a problem.

Remember, no one claimed to be technical expert on ST, and unless you
get a paycheck from ST's R&D department you may be "JUST
> BLOWING IT OUT OF YOUR BUTT".

I am off the soap box now, I am going to go back to having fun.

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

[Wayne Armstrong]

Here is some advice, get a life and learn to capitalize properly. What I
said is absolute truth for sea level conditions.

BROCKKM <bro...@aol.com> wrote in message
news:19990531024603...@ng-cg1.aol.com...

[BROCKKM]

Wayne Armstrong,
I HAVE ABOUT 13 S.T. .45'S I HAVE FLOWN THEM IN ARIZONA AT THE ELEVATION OF
2,700
I HAVE ALSO FLOWN THEM IN TEXAS AND CALI ON THE BEACH IS THAT SEA LEVEL ENOUGH
FOR YOU. IT SOUNDS LIKE YOU NEED TO CHECK YOUR SETTINGS BECAUSE I DON'T SEEM
TO HAVE ANY PROBLEM

[CUBBY1999]

>Here is some advice

Wayne,
I hate to tell you this but your ego is to high for the low I.Q. answers you
are giving. Brockkm also had his caps lock on. I could even see that much. I
have to agree with him on his combination of engine, fuel and plug choice. I
fly the same in McAllen, Texas. I have a Great Planes Ultra Sport 40 with a
Super Tigre .45 in it. I am running Wings 15% fuel and also an O.S. A3 glow
plug. Why don't you try this combination and see how well it works.

P.S. Nitro supports combustion! Especially when you are at high altitudes!
(I have seen people run their engine off of 100% nitro once. trust me it will
bring power to your engines.) Try some in your engines.

[BROCKKM]

> If your running anything over 5% Nitro you need to add
>an additional head gasket.

SHOWS HOW MUCH YOU KNOW AGAIN (VERY LITTLE) I HAVE NEVER BOUGHT A GASKET FOR
MINE AND I'M RUNNING 15% .45 10X7 GETTING 14,000+ RPM
BEAT THAT!

[JMarsh Q52]

Hello.....
I am a modeler that has been in the hobby for over 50 years...and I still fly
competively... won my share of the big trophies and national accolades....and
by choice, I run Super Tigre engines, as far as my money goes they are among
the finest peices of engineering in the world... fast cars, fast women, and
fast engines... the Italians know what works.

In your letter you said that you had a problem with your ST 40 running at mid
range. you didnt include enough information to help ID your problem. To help
you cure your operation problem I would have to know what brand of fuel & nitro
content you are using. The type of glo plug you have installed, whether it is
an idle bar or standard plug and the brand. The mount position of your fuel
tank and dont forget the prop... Also, did you have the stock muffler
installed and pressure to the tank. There are several other items, but the
things that I mentioned beforehand are needed to pin point your engine
problems. one last item....is this your first experience with model aviation or
40 size motors?

To give you some idea of my experiences I am good freinds with Geo. M. Aldrich
( Mr. Super Tigre) an AMA hall of fame member and internationally renowned
guru to the CL stunt community and Ace model designer..... I have gained a lot
of knowledge from this man and I might as well pass on what I know or help I
can assist you with.
Jim Marshall......JMarshQ52@aol.com

[Jim White]

let me throw my 2 cents in..... the MOST common reason for complaints
of "poor midrange" from relative newbies owning Super Tigre's, is a
misplaced fuel nipple.... now, I DON'T mean they lost it, just
purposely misplaced it.... you see, it's so easy to loosen those two
screws up on the side of the carb, and re-position the fuel nipple so
that it's a little easier to pop off the fuel line and fill the
tank.... thanks to our overzealosuness to KISS, 98% of the world has
gone to two line tanks and eliminated the 3rd fill line.... that's
another story.... but having moved the fuel nipple (usually upwards),
they've upsewt the fuel mixture in the mid range by rotating the spray
bar....easy to fix, check for the marks from the screw heads when the
factory torqued 'em down, and rotate it back....

as far as the debate on nitro and extra head gaskets, just remember,
relatively high compression and relatively higher nitro content will
run.... the top end will improve dramatically untill the point of
detonation is reached.... and with modern chamber design, the
tolerance level has moved upwards.... but the secondary effect is what
we old farts call "handling".... that elusive quality which makes an
engine 'sweet".... as you raise the compression and or nitro, it
starts to go away.... on the other hand, too little (as in none) nitro
can adversely effect handling as well.... like all good things in
life, it's a compromise.... more is not always better...

jmar...@aol.com (JMarsh Q52) wrote:

Jim White
AMA 2466
WB2WOY
WPMPA/BCF/PFC
SouthShoreSoftware
Treasure Island, FL

[David Ivory]

Jim

As they come out of the factory, our ST's in the UK seem to have the
spray bar set wrong. The fuel nipple should point directly at the
front mounting bolt hole, and this is how I run mine.

BTW I had a real tricky problem with a G90, where the low end needle
had become free from its home in the brass low end adjustment boss,
with the result that it migrated up the spray bar, leaning accordingly
with the inevitable end result. Other than that, my ST's have been
fine to set up: high end first, then the tilt test to get the low end
right. I have not even found them particularly sensitive to tank
level, they seem to pull their fuel well., though periodic pinholing
of the plumbing lines needs to be regularly checked for as with any
engine - I just pressure test by old fashioned means 8-)

David Ivory
Cold welding solutions
for balsa and soil.

[Wayne Armstrong]

The problem is more pronounced with the larger size Super Tiger 75's & 90's.
Even worse if you use an after market in the cowl muffler. Its less
noticeable on the 45 size engines if propped for high RPM like you seem to
be doing. Even so, try a head gasket you may actually gain more top end RPM.

Oh, and how about sea level, high temperature and high humidity? Welcome to
South Louisiana.

BROCKKM <bro...@aol.com> wrote in message

news:19990531223552...@ng-fi1.aol.com...

[Wayne Armstrong]

So, that would explain why all the letters were capitalized..... Ok, the
smaller Supertigers exhibit less of the symptoms of detonation from high
compression, especially if ran at high rpms. Still the reasoning is sound,
what I'm am talking about is engine timing. Timing in a semi diesel engine
is affected by many things, not limited to compression, needle setting,
plug, fuel, temperature, humidity, rpm. The slightly over compressed Super
tigers can cause the high speed to be set slightly richer, which results in
an overly rich mid range. By lowering the compression slightly the timing
will be retarded, allowing a leaner high speed and a leaner mid range.

Also, if you run a tuned pipe the compression should generally be lowered to
get maximum power. Because pipes increase effective engine compression.

Oh yea, Nitro Methane is an oxidizer which helps get more Btu's in a given
displacement. The result is more power, as in dragster power.

Wayne

CUBBY1999 <cubb...@aol.com> wrote in message
news:19990601012454...@ng-fi1.aol.com...