The complete radio control model airplane FAQ.  


What about the Super Tigre 2300 (ST2300, G2300 G-2300, or 20-23) model airplane engine?

The Basics

History, by Dick Hanson

AM Cross's notes


Additional How-To pages:

Dick Hanson's header & pipe setup

Bob Pastorello's pages...

    New Motor Checks

    Super Tigre 2300 General Setup Info

    CARB Modification   

    Modified Carb Drum

ST2300 Engine Setup--GOOD Page--with information provided by the legendary 2300 Guru Dick Hanson

Pe Reivers' 2300 modifications for perfect throttle response

ST's Super Tigre 2300 Spec's



The Basics

    I've still got to put mine onto a test stand, so I haven't run mine. Basically from reading and asking around, I've found that there are two types of owners: Those who curse them, and those who praise them. The cursers just haven't done the mods or else found that little glitch. Those who praise are either lucky or else diligent at getting them right. Mine, for instance, had the fuel hose barb that was almost plugged by a machining burr, and I wouldn't have found that problem had the fix of drilling it out not been suggested by AM Cross, with several of her newsgroup posts copied below.

    Other tips--mainly discussing the carb modifications--can be found following this text.  There is a separate little section just for the 2300. For those who have taken the time to cut their carbs, they have nothing but good things to say about these engines. I've yet to hear one complaint from somebody who's done the full mod to it.

    Another more costly but simpler option is to replace the ST carb. The Perry Carb will work as a straight bolt-on for about $45. (Even with that carb, though, the 2300 is still a bargain for the amount of power it puts out.) Another option is the OS 7D carb. To do this, you'll need an adaptor, as the OS has a different mounting OD. The Tower part is # LXFY95 22022014 REDUCER RING S2K-TWIN but they are often on BO, and now their web page declares it temporarily unavailable. The size is 17mm OD x 14.5mm ID x 14mm long. Those who have used this carb have been thrilled with the throttle response, and have experienced either no power loss or negligible power loss (50-100 rpm). That would probably depend on the prop size used.

    Here's one happy ST customer's comments: I Ended up going with the OS7D carb and only lost 100rpm over the ST carb. I just didn't want to mess with the ST carb so I replaced it. MY ST 2300 carb, like so many others, idled well and top-end was phenomenal but that midrange and transition was ...blech! Transition with the OS carb was phenomenal. Mr. Pete, TX

    Another fix that has been tried is to use a Tower SUPG2420 22623366 CARB RESTRICTOR 3000K US$4.99. This fits into the carb, and increases the fuel draw...at the expense of top end performance. (I suppose that would be dependant on your prop size.)


History, by Dick Hanson:

St2300 - easily one of the most powerful/light engines ever done-Here is what happened :
ST released the first version with a very large, conventional carburetor. I got one of the first. It was obvious that the carb would not draw fuel properly the way it was configured. Why? The design changes mixture as the barrel rotates and this "relative fuel to air mix" was excellent when the barrel was almost closed and the engine was sucking hard on the spray bar as well as the air thru the carb air supply. as the engine reached full opening, the fuel "suction" really got diminished. Way too much air for the fuel available. Just not enough suction from the crankcase at wide open throttle and lower (8000) rpm's.

Super Tigre intended there to be pressure from the tank - and on the FIRST production run - the single outlet muffler would provide fair pressure - about 1/4 lb. (I measure tank pressures with a quality 0-5 lb gauge). The next production engines had a bastardized carb with a tiny bore in the bottom half and a reworked throttle opening control slot. Worse yet -a dual outlet muffler - ! This combo effectively killed any tank pressure and wrecked the air/fuel mix. How /who/why this was done is a mystery still - My best guess is that they were trying to get more rpm with the dual outlet muffler and the carb redesign - well, that was simply an error.

Many users wanted an in cowl muffler - none of these provided correct tank perssure. the best I ever saw was under 1/4 lb with one stack closed off. Pumps/regs were added by many with results from awful to ok. The real fix -was to duplicate the first muffler and carb (for an engine running smaller props such as a 15x8) which worked fine on faster revving setups.

For real power though - on props such as 18x8 which would turn over 9000 rpm, the setup was a F glow plug -25% nitro and oil, the original carb setup -(or a later one redone to original specs and MOST important - a header and tuned can which brought up pressure from zero at low speeds to over 1/2 lb -up to 3/4 lb at full rpm.

The pumped setups I saw ALL, (thats's ALL), had so/so transition at lower speeds unless the top speed was still on the lean side. The net result - premature ring wear. 


I sold all my ST stuff and went to the ZDZ40 for the power I was after for 1100-1200 sq in models. I also got tired of pouring a a gallon of 15 buck fuel thru in a single day. But if glow fuel were a couple of bucks a gallon - I would have kept the Tigres.


Here is the latest word from AM Cross:


The G2300 sets up a little differently from smaller or larger Tigres. (Please remember we are solely the US distributor. If you are outside the US, you may wish to contact the ST distributor in your region of the world, as your choices of fuel/plug, etc may affect its performance.)

First, the engine needs to be lean on top, as lean as you can possibly go without detonation.

Second, the engine needs to idle low...below 2500 and preferably in the 2000 or less range.

Third, the engine MUST be fed high quality high oil (18%+, at least partially castor) fuel. It will run on FAI fuel but prefers nitro in the 5-25% range.

This sport engine performs fabulously under these conditions for most sport pilots. It is a real powerhouse and work horse of a sport engine. However, this reasonably price sport-performance engine is not designed or able to perform for extended lengths of time in the 2500-4000 range. If you choose to ask it to do so, you must come back to idle prior to applying full throttle to clear the carburetor, *OR* supply the engine with significantly higher fuel delivery pressure by utilizing a high volume pump such as a *Varsane Perry VP30 Regulating Pump* while also using muffler pressure. (Please see note below on pump set up requirements.)

If the above steps do not resolve your concerns, then look to the muffler you are running. Fuel flow is a key concern of this engine, requiring good pressure to the fuel tank. In order to increase muffler pressure to the fuel tank, a twin exhaust outlet muffler needs to have the second stack partially or completely blocked. The same is true of exhaust systems made by other vendors, such as Bisson, or Slimline.

We've had excellent results using a Super Tigre "Silent Muffler" for the S-2000/2500, although it's a bit large, and doesn't hide at all well inside engine cowlings.

The pump should be adjusted to leave only a 1/32" gap.
Keep the pressure line as short as possible.
Set the pump first DO NOT set your carb and try to match the pump to the carb.
Use exhaust pressure with the pump. [Note that Perry specifically advises against this. rcfaq]

Mrs. AnnMarie Cross


Previously, AM Cross offered these suggestions:

You have two choices to resolve this, either is effective, but our R&D staff have found increased power with the first approach increasing fuel volume. This is done by running larger fuel line, no pump, using a twin outlet exhaust such as the stock exhaust or the BCM pitts muffler, and enlarging the fuel nipple off the carb from .051 to .074. This dramatically increased the fuel consumption, the power output, and the overall performance.

Your second option is to increase pressure to the fuel tank. This increases the fuel pressure, which allows the high-speed needle to be set a bit farther in, which leans the midrange. In order to increase muffler pressure to the fuel tank, one of the exhaust outlets of the stock muffler must be partially or completely blocked. The same is true of exhaust systems made by other vendors, such as Bisson, or Slimline.

We've had excellent results using a SuperTigre "Silent Muffler" for the S-2000/2500, although it's a bit large, and doesn't hide at all well inside engine cowlings.

Adding a reducer inside the carburetor winds up being as effective, since it will improve fuel draw at all throttle settings. It will be easier to balance the high-speed and low-speed needles.

Most of the fliers in the US have tried increasing muffler pressure to the fuel tank to increase fuel flow, rather than try making an insert to fit into the carburetor. Please note that the 2500s restrictor will NOT fit.

I hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.) You can also reach our product support technical team at 217-398-8970, or via fax at 217-398-7721.


Mrs. AnnMarie Cross

Product Support Manager
Great Planes Model Distributors



Super Tigre 2300 on gasoline...


I sent my 2300 out to Air Hobbies to upgrade the rod bushings to roller bearings. I plan to run the engine by the middle of February (hopefully sooner...). I am very interested in how it will compare to the RCS 1.4.


The cost breakdown...


Install a hardened sleeve on crankshaft:

Install Needle bearings on the Rod: $30
Walbro carb adaptor w/hose fittings: $18
Total: $68
add the engine $189

add a CH Ignition w/SyncroSpark:

(which I already own)




(about the same as the RCS price)



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