ST2300 Testing and Experimenting
03-05-2006, 11:10 PM
#226
RE: My 2300 only likes one prop
ORIGINAL: aerobob
I don't hang out in glow engines much anymore, as I've seen the light and started running gassers.... however, I see my name and website being promoted, so thought I'd throw in a comment or two...
First - there has been MAJOR grief with the ST 2300 since it was introduced. It is a very "finicky" motor to get setup reliably and consistently, but it can be done without buying a bunch of after market crap and adding to the wallet depletion.
Second - by design, the motor is supposed to be an "rpm" motor... it is not meant to be lugged with a huge prop load that reduces it's peak rpm range. WHen it gets loaded to that extent, two very important things happen --- one, motor internal temps go through the roof, and if running synthetics, you get scored pistons and destroyed rings and two - there is not enough fuel flow through the motor to properly cool it (fuel going through takes a lot of heat with it out the exhaust).
Third - any motor dies, and nearly any dead motor causes problems. My most recent deadstick destroyed a nearly new GP Ultimate. Ugly. But it happens.
The STOCK ST can be made to run VERY well by following the instructions that come with it. No matter what anybody says to the contrary, this motor is NOT a powerhouse like a OS 1.60 or Moki 1.80.... ain't gonna be, and never was meant to be, and it needs nitro and smaller props. End of story.
Pumps can help - but I have seen them add to a person's woes more than once. Perry carb is good (until you learn how totally screwed up their low end mixture design is) but it ain't gonna make the motor run. Back pressure is needed from a muffler to make the carb draw most efficiently. True story. Rotating spray bars, running idle bar plugs, 30% nitro (cannot believe ANYONE is actually saying to DO that) and all the other stuff MAY help someone....
My suggestion - FWIW - go back to the basics, follow the instructions, make sure the fuel is CLEAN, filtered IN the airplane, that the tank orientation is correct to the venturi, and that the rear end of the clunk isn't more than 12-14" from the VENTURI. And for God's sake - do NOT run all-synthetic....
Signing off now - I sure hope you guys get the motors running well. They are very capable of consistent, reliable performance.
I don't hang out in glow engines much anymore, as I've seen the light and started running gassers.... however, I see my name and website being promoted, so thought I'd throw in a comment or two...
First - there has been MAJOR grief with the ST 2300 since it was introduced. It is a very "finicky" motor to get setup reliably and consistently, but it can be done without buying a bunch of after market crap and adding to the wallet depletion.
Second - by design, the motor is supposed to be an "rpm" motor... it is not meant to be lugged with a huge prop load that reduces it's peak rpm range. WHen it gets loaded to that extent, two very important things happen --- one, motor internal temps go through the roof, and if running synthetics, you get scored pistons and destroyed rings and two - there is not enough fuel flow through the motor to properly cool it (fuel going through takes a lot of heat with it out the exhaust).
Third - any motor dies, and nearly any dead motor causes problems. My most recent deadstick destroyed a nearly new GP Ultimate. Ugly. But it happens.
The STOCK ST can be made to run VERY well by following the instructions that come with it. No matter what anybody says to the contrary, this motor is NOT a powerhouse like a OS 1.60 or Moki 1.80.... ain't gonna be, and never was meant to be, and it needs nitro and smaller props. End of story.
Pumps can help - but I have seen them add to a person's woes more than once. Perry carb is good (until you learn how totally screwed up their low end mixture design is) but it ain't gonna make the motor run. Back pressure is needed from a muffler to make the carb draw most efficiently. True story. Rotating spray bars, running idle bar plugs, 30% nitro (cannot believe ANYONE is actually saying to DO that) and all the other stuff MAY help someone....
My suggestion - FWIW - go back to the basics, follow the instructions, make sure the fuel is CLEAN, filtered IN the airplane, that the tank orientation is correct to the venturi, and that the rear end of the clunk isn't more than 12-14" from the VENTURI. And for God's sake - do NOT run all-synthetic....
Signing off now - I sure hope you guys get the motors running well. They are very capable of consistent, reliable performance.
03-06-2006, 07:53 AM
#227
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RE: My 2300 only likes one prop
Not24 Did your ST carb have the flat bar or round spraybar. Think about this. That ST carb you were trying to restrict is the same carb on Super Tigre's from 40-45-51-61-75-90-2000-2300-2500-3000 except most got the flat spraybar at 61 and up to increase air flow a little. There are far to many of these carbs out there to be considered really bad. The Moki at 30 pounds makes it an expensive choice like the OS7. There is one old time fix I've heard about but never tried. The fuel nipple which is med tubing size is fine for smaller tigres but restrictive for the larger ones. Rather than try to drill out nipple. Take it out and solder a longer brass tube in it's place. Since the tube has no barbs it needs to be longer to hold tubing on or a clamp. You now have a passage 3 times as large.
03-06-2006, 01:47 PM
#228
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RE: My 2300 only likes one prop
I found Aerobobs comments very intertaining but not in sync with what I have experienced. I started simple and tuned those needles till they were ready to fall out but no consistent midrange and random deadsticks. After spending all summer trying to get this thing going is when I started trying pumps etc. but with no luck. The pump for this engine is not the answer. I fully believe that if I had another carb that my engine would perk up like Not24s. Later this spring I plan on going that rout and purchase a carb. The first think that came to my mind while reading his comments were exactly what Not24 said about some motors being good runners and other not. I don't doubt that many people have 2300 that run well but mine would not so I have spent over a year trying differnt things. My last thing to try is the carb and if that doesn't do it then forget it.
03-06-2006, 02:11 PM
#229
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RE: My 2300 only likes one prop
The ability of that motor to operate in midrange is absolutely, completely tied to the angle of the groove in the drum rotor. That, and the concentricity of the spray bar where it rotates as it opens the cat's eye at the end of the idle needle. If your spraybar is NOT absolutely concentric, or the needle o rings slightly worn, permitting the idle needle to wobble - you will NEVER EVER get a reliable and smooth transition. Very few folks get into that carb deep enough to understand the mechanical tolerances and interplay between that low speed needle, the venturi, and it's impact on the high speed. Then, of course - ALL of that interplay is controlled by two things -
1. Tension of the spring that is pushing the drum rotor toward the low needle and 2. The machining tolerance of the rotor GROOVE and the SET SCREW that controls the rate of angular change during rotation. That set screw can wear, it does wear, the spring can get weak, which then means it doesn't resist the drum rotating of the low needle (and THAT is what causes the throttle-up-rich-and-die-transition).
I could go on, but I doubt anyone is really truly interested in learning the vagaries of the internal workings of the STOCK carb.
It's all about tolerances.
Whether you agree, or don't, is irrelevant.
My facts are irrefutable from physical evidence.... learned painfully at the U. of H. K.
1. Tension of the spring that is pushing the drum rotor toward the low needle and 2. The machining tolerance of the rotor GROOVE and the SET SCREW that controls the rate of angular change during rotation. That set screw can wear, it does wear, the spring can get weak, which then means it doesn't resist the drum rotating of the low needle (and THAT is what causes the throttle-up-rich-and-die-transition).
I could go on, but I doubt anyone is really truly interested in learning the vagaries of the internal workings of the STOCK carb.
It's all about tolerances.
Whether you agree, or don't, is irrelevant.
My facts are irrefutable from physical evidence.... learned painfully at the U. of H. K.
03-06-2006, 05:02 PM
#230
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RE: My 2300 only likes one prop
ORIGINAL: speedster 1919
Not24 Did your ST carb have the flat bar or round spraybar. Think about this. That ST carb you were trying to restrict is the same carb on Super Tigre's from 40-45-51-61-75-90-2000-2300-2500-3000 except most got the flat spraybar at 61 and up to increase air flow a little. There are far to many of these carbs out there to be considered really bad. The Moki at 30 pounds makes it an expensive choice like the OS7. There is one old time fix I've heard about but never tried. The fuel nipple which is med tubing size is fine for smaller tigres but restrictive for the larger ones. Rather than try to drill out nipple. Take it out and solder a longer brass tube in it's place. Since the tube has no barbs it needs to be longer to hold tubing on or a clamp. You now have a passage 3 times as large.
Not24 Did your ST carb have the flat bar or round spraybar. Think about this. That ST carb you were trying to restrict is the same carb on Super Tigre's from 40-45-51-61-75-90-2000-2300-2500-3000 except most got the flat spraybar at 61 and up to increase air flow a little. There are far to many of these carbs out there to be considered really bad. The Moki at 30 pounds makes it an expensive choice like the OS7. There is one old time fix I've heard about but never tried. The fuel nipple which is med tubing size is fine for smaller tigres but restrictive for the larger ones. Rather than try to drill out nipple. Take it out and solder a longer brass tube in it's place. Since the tube has no barbs it needs to be longer to hold tubing on or a clamp. You now have a passage 3 times as large.
It's got the round spraybar. The fuel nipple is not the point of restriction on the carb. The diameter of the hole thru the spraybar is. Even given that, fuel flow is not the issue with the ST carb. It flows plenty of fuel. Its problem is that it doesn't DRAW fuel. It doesn't atomize the fuel properly and spits raw fuel out the exhaust. It'll do this at any power setting. The venturi is just simply too large and takes in too much air, so to get a good running mixture you need to load it up with fuel. By reducing the air intake, you increase the intake velocity, which aids in fuel draw. Now that you have less total air entering the engine, you need less fuel to mix with it to get the mixture right. By injesting smaller gulps of fuel and air, the atomization is better, and fuel economy increases. Now just prop it right, and you don't even realize a loss of power. Is the size of the venturi the only issue with the ST carbs? I don't think so. I think there are many contributing factors, manufacturing tolerances being a big one.
03-06-2006, 06:11 PM
#231
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RE: My 2300 only likes one prop
aerobob - Bob, I've downloaded your tuning tips from your website (a long time ago!) and have 20+ years in the hobby. I consider myself reasonably decent at tuning engines (I'm an aircraft mechanic). I know what you mean about the criticality of the carb needle being centered in the spray bar, but my carb never metered correctly across the entire RPM range from new, i.e. right out of the box. Many have reported similar experiences, so it's not a "wear" issue - it's got to be design, manufacture/assembly, etc... I suspect that S.T.s machining (just of the carb I'm talking here) and/or quality control may also be at fault. Too many people that are otherwise experienced, successful modelers report woes with this engine. I'm not in any way putting down your extensive experience or your post, but there has to be a real (not perceived) problem with these carbs. People swap carbs and get instantly better transition - doesn't that say it all? O.S. must have made a killing already selling the O.S. 7D carbs for the big tiggers - look, a readily available adaptor sleeve!!? You don't exactly see this every day do you. These 2300s and the 3250s are performance bargains, but I'm not crazy about the stock carbs.
03-06-2006, 06:21 PM
#232
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RE: My 2300 only likes one prop
Daryl, you are EXACTLY correct. I wasn't saying "the design is good"; I was sharing that the reason it is so hit and miss is the ol' proverbial "expansion of tolerances in all directions". I truly think that could be an issue with this motor, with the "average" being the ones that royally SUCK.... and the ends of the bell curve being "won't run no matter what" and "runs fine per instructions".
My findings and experience simply is shared to help anyone on the good end of the tolerance curve.
The solution for everyone else, IMHO, is a different motor.
The ST2300 is a PRIME example of throwing good money after bad, and a person who can't see the forest for the trees just keeps on investing.
It ain't NEVER gonna be a silk purse..............
My findings and experience simply is shared to help anyone on the good end of the tolerance curve.
The solution for everyone else, IMHO, is a different motor.
The ST2300 is a PRIME example of throwing good money after bad, and a person who can't see the forest for the trees just keeps on investing.
It ain't NEVER gonna be a silk purse..............
03-06-2006, 06:27 PM
#233
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RE: My 2300 only likes one prop
Darned - I guess that's why all the pattern guys so quickly abandoned them. I had mine originally in a Midwest Giles. Killer combo, but the engine really only ran great flat out. No shortage of power. Too bad, I was really hoping S.T. would knock O.S. off their post a little and bring the price of pattern engines down from their exorbitant levels. I can seriously see the advantage of going gas, especially for pattern guys putting lots of training flights in. If nothing else, these engines are available cheap.
03-06-2006, 07:06 PM
#234
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RE: My 2300 only likes one prop
I with Not24 on this issue the carb venturi is too large and the metering isn't right, plane and simple. A simple carb swap should solve the issue. Question is which carb is the best OS, Magnum, Jett, Moki and how much will it cost? The 2300 at $125 and the cost of a good carb will still be cheaper than some other engines out there. I am going for it.
03-06-2006, 08:54 PM
#235
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RE: My 2300 only likes one prop
Not 24 That same carb on a ST .40 should just flood that engine with fuel , but they don't. Cause a 1.40 spits out raw fuel at all levels. The round spraybar is fatter and takes up more volume in venturi limiting air flow. The flat spraybar takes up less volume to allow more air to come in and produces more suction to get more fuel to feed a 1.4 cu engine. I forgot if you have the dogleg slot barrel or the straight angle cut. If it were my carb I would make sure I had the flat spraybar and straight cut barrel grove. You can take a file and flatten the round spraybar on both sides. Now that you butched the cats eye it is probably shot. Drill out the nipple a little larger and use large fuel tubing from tank. Center the cats eye in venturi even..... (9:00) level nipple. turn low needle in till it blocks off the cats eye half way. Turn out the HS needle 3 turns. 17" prop. get close but rich high speed and lean the LS needle for pinch test with 100RPM increase. But thats me. Super Tigre admitted the round spraybar in some carbs was wrong and the dogleg slot was a misstake.
03-06-2006, 11:07 PM
#236
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RE: My 2300 only likes one prop
ORIGINAL: speedster 1919
Not 24 That same carb on a ST .40 should just flood that engine with fuel , but they don't. Cause a 1.40 spits out raw fuel at all levels. The round spraybar is fatter and takes up more volume in venturi limiting air flow. The flat spraybar takes up less volume to allow more air to come in and produces more suction to get more fuel to feed a 1.4 cu engine. I forgot if you have the dogleg slot barrel or the straight angle cut. If it were my carb I would make sure I had the flat spraybar and straight cut barrel grove. You can take a file and flatten the round spraybar on both sides. Now that you butched the cats eye it is probably shot. Drill out the nipple a little larger and use large fuel tubing from tank. Center the cats eye in venturi even..... (9:00) level nipple. turn low needle in till it blocks off the cats eye half way. Turn out the HS needle 3 turns. 17" prop. get close but rich high speed and lean the LS needle for pinch test with 100RPM increase. But thats me. Super Tigre admitted the round spraybar in some carbs was wrong and the dogleg slot was a misstake.
Not 24 That same carb on a ST .40 should just flood that engine with fuel , but they don't. Cause a 1.40 spits out raw fuel at all levels. The round spraybar is fatter and takes up more volume in venturi limiting air flow. The flat spraybar takes up less volume to allow more air to come in and produces more suction to get more fuel to feed a 1.4 cu engine. I forgot if you have the dogleg slot barrel or the straight angle cut. If it were my carb I would make sure I had the flat spraybar and straight cut barrel grove. You can take a file and flatten the round spraybar on both sides. Now that you butched the cats eye it is probably shot. Drill out the nipple a little larger and use large fuel tubing from tank. Center the cats eye in venturi even..... (9:00) level nipple. turn low needle in till it blocks off the cats eye half way. Turn out the HS needle 3 turns. 17" prop. get close but rich high speed and lean the LS needle for pinch test with 100RPM increase. But thats me. Super Tigre admitted the round spraybar in some carbs was wrong and the dogleg slot was a misstake.
ST carb .560/.430/.460 (barrel)
Magnum carb .590/.455/.388 (barrel)
As you can see, these dimensions are very different. The most noticeable difference is that on the ST carb, the hole in the barrel is bigger than the base of the intake, and the magnum carb has that hole quite a bit smaller than the base of the intake. Bernoulli's theory says that as velocity increases, pressure decreases. The velocity in a venturi is the highest where the diameter is the smallest. This puts the vacuum upstream of the spraybar in the ST carb, and at the spraybar in the Magnum carb. The spraybars are not the same diameter, with the ST one being larger. The amount of choke that the spraybar adds is only that. It is more of an obstruction to the flow than an increaser of the velocity due to reduction of area. I'd say that to get the ST carb to function properly, one thing to try is to sleeve the barrel to a diameter that is smaller than the base of the intake. .400" looks like a number that would work. My engine runs fine with the Magnum carb, so I'm not going to play with the st carb any more. Maybe in the future my curiosity will get the better of me, but for now, I am done. My testing from this point on will be limited to fuel and propellers.
03-07-2006, 10:17 AM
#237
RE: My 2300 only likes one prop
ORIGINAL: Not24
ST carb .560/.430/.460 (barrel)
Magnum carb .590/.455/.388 (barrel)
The velocity in a venturi is the highest where the diameter is the smallest. This puts the vacuum upstream of the spraybar in the ST carb,
ST carb .560/.430/.460 (barrel)
Magnum carb .590/.455/.388 (barrel)
The velocity in a venturi is the highest where the diameter is the smallest. This puts the vacuum upstream of the spraybar in the ST carb,
03-07-2006, 04:42 PM
#238
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RE: My 2300 only likes one prop
I just threw that out there to see if anyone is paying attention. Good job! There are other differences in these two carbs bseides the diameters. The cat's eye's are cut differently, and although I didn't measure, the needle diameters and fuel passages may be different sizes. For whatever reason, and i really don't care at this point, the Magnum carb works like it should. It has a very broad range of adjustment with the high needle, yet it is sensitive at its optimum setting. It still allows the engine to produce plenty of horsepower, and maybe a little more because of the less restrictive exhaust. I'm looking forward to running the 16-8 and 16-10 props to see what they'll do.
03-07-2006, 10:09 PM
#239
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RE: My 2300 only likes one prop
Here is my 2300 story. Returned engine to Hobby Services after running 2/3 gal. fuel through due to low compression and max revs of only 6000 w/ Zinger 18-6-10. Engine returned in 8 days (thanks HobbyServices) w/ new ring, liner, front and rear bearings. Engine re-mounted and using info from this thread, (thanks guys), I installed 17-6 apc, 0s-f. Began break-in all over, using ST instructions. Experienced most or all the same symptoms discussed in this forum, including flame-outs, slow or stumbling acceleration, more flame-outs, etc. Began to get frustrated, but kept running fuel thru, and after about 4-5 tanks engine was spinning about 9500. The motor quit flaming out at about 1 1/2 gallons fuel. After 2 gal. I decided to fly it. I changed from 5% Omega to 10%, and have flown 6 flights over 2 days. 2300 has not even hinted at stumbling or dying. Runs great. I have thrown every manuever I can think of (except hovering) at it , it won't die. Only issue is slow acceleration, but to me that is only problem for hovering low, and i didn't buy it for 3-D. Also idles well, 1500 for landing, 2300 for flying, (mechanical trim on 9303). Plenty of power for 11 lb. Edge. I thank all you for your input. It was very informative. Regards, Bill.
03-07-2006, 11:07 PM
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RE: My 2300 only likes one prop
Bill, Glad to hear you got some use out of this thread. May your 2300 provide you many happy flights and smooth landings.
Eddy
Eddy
03-07-2006, 11:58 PM
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RE: My 2300 only likes one prop
Speedster, I don't think I did anything to it. I followed ST's instructions for break-in to the letter, slowly leaning the engine to just below peak rpm. After 4 tanks of fuel, the best I could get was about 6000 rpm, and the engine had almost no compression. I sent it in to Hobby Services and they fixed it. They gave no explanation for the bearing replacement. Not 24, thanks and I hope you get yours going too. After reading of your success with a different carb, I may try that also in the future. Regards, Bill
03-08-2006, 11:12 AM
#244
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RE: My 2300 only likes one prop
Cyclic, therea are plenty of people out there that augment their spouse by doing breast enlargments, etc. and some even pay for counseling. Not saying I have done this but only have heard of it. Just a little humor for those reading this form with nothing better to do.
03-08-2006, 11:40 AM
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RE: My 2300 only likes one prop
That's the best one Ive read to this thread so far. Congrat's to all who are having successes. I have a 2300 and for the third time im running os f plug 15% omega and a 17x8 apc prop. This combo is awesome on my seagull laser 200. unlimited vertical good speed and some decent 3d. I must say if I had to screw around with the engine dialing in it to run I would do something else. Probably fly another plane. Again thanks for all the feedback.
03-08-2006, 12:29 PM
#246
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RE: My 2300 only likes one prop
"People swap carbs and get instantly better transition - doesn't that say it all?"
Yes. If you're not into diddling with a carb to make it perfect, by all means replace it. But you do not need to spend all of that money for an OS 7D carb. Many have found satisfaction using Magnum/ASP/SC carbs. By the time you add the price of an OS7D carb to the price of the G2300, you are within hollering distance of the OS 1.60FX. I have had excellent results using Magnum/ASP/SC carbs on those engines. Of course, you can wind up owning another less than perfect carb within those brands, but you could buy two or three of them for the price of an OS7D carb.
I agree with others' diagnoses of the ST carb problem. I was fortunate in that my first G2300 was perfect out of the box. I hope my new G2300 will run as well without tinkering.
Yes. If you're not into diddling with a carb to make it perfect, by all means replace it. But you do not need to spend all of that money for an OS 7D carb. Many have found satisfaction using Magnum/ASP/SC carbs. By the time you add the price of an OS7D carb to the price of the G2300, you are within hollering distance of the OS 1.60FX. I have had excellent results using Magnum/ASP/SC carbs on those engines. Of course, you can wind up owning another less than perfect carb within those brands, but you could buy two or three of them for the price of an OS7D carb.
I agree with others' diagnoses of the ST carb problem. I was fortunate in that my first G2300 was perfect out of the box. I hope my new G2300 will run as well without tinkering.
03-08-2006, 02:55 PM
#247
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RE: My 2300 only likes one prop
Ed, Thanks for supporting my conclusions. You have a very good way of making your point clearly and without bias. Your input and comments are always welcome. Thank for contributing.
03-09-2006, 04:59 PM
#248
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RE: My 2300 only likes one prop
Hello Ive spent the better part of this morning reading this thread from start to finish,I have owned many ST engines in my life and a 2300 was the last on the list .Maybe I'm a lucky one but it runs flawless,Using the bisson muff with one pipe closed off 15% nitro fuel 18% oil,and a 16/8 APC Prop .I have wrote this many times in these forums the 2300 is not a lugger, it does not like to swing the 18 inch props very well , for those who are getting in the 9000 rpm range with a 18 inch prop ,you have a screamer IMO. My engine is on a GB Sukhoi thats about 11lbs It does a wonderful job pulling this plane at my altitude.Which is 4500.
OK I seen this in a few places seems that everyone is under the impression that rotating the spray bar leans the engine out ,no matter which way its turned .My experience says that is not so!I went through the manual and cant find anything about it on the 2300.But I know it was mentioned in the other manuals for the G-90 and so on .Anyway for a engine that is running to rich in the midrange I turn the spray bar to wards the front of the carb, if its to lean I go the other way.I have always liked this third adjustment, it has let me dial in a engine to its max performance.
I seen the question asked how it com-pairs to the OS 160 FX ,just so happens I have two of the Sukhois one with the ST and one with the OS .Although the ST flies the plane very good with power to spare, it wont hold a candle to the OS 160.
Not 24 I am glad you didn't give up and found a solution to your probs.I hope it runs great in your new bird.I think you will like the smaller props ,spool up time is scary *S* Almost instant in my case.I wouldn't have any reservations about buying another 2300, even if I had to replace the carb.in my book there ok ! Oh and as far as the 2300 having the power of a 180 saito,*LOL* The saito is a good engine and will swing the 18 inch props but IMO it wont stay with the ST .Anyway good thread enjoyed reading it .
OK I seen this in a few places seems that everyone is under the impression that rotating the spray bar leans the engine out ,no matter which way its turned .My experience says that is not so!I went through the manual and cant find anything about it on the 2300.But I know it was mentioned in the other manuals for the G-90 and so on .Anyway for a engine that is running to rich in the midrange I turn the spray bar to wards the front of the carb, if its to lean I go the other way.I have always liked this third adjustment, it has let me dial in a engine to its max performance.
I seen the question asked how it com-pairs to the OS 160 FX ,just so happens I have two of the Sukhois one with the ST and one with the OS .Although the ST flies the plane very good with power to spare, it wont hold a candle to the OS 160.
Not 24 I am glad you didn't give up and found a solution to your probs.I hope it runs great in your new bird.I think you will like the smaller props ,spool up time is scary *S* Almost instant in my case.I wouldn't have any reservations about buying another 2300, even if I had to replace the carb.in my book there ok ! Oh and as far as the 2300 having the power of a 180 saito,*LOL* The saito is a good engine and will swing the 18 inch props but IMO it wont stay with the ST .Anyway good thread enjoyed reading it .
03-10-2006, 06:57 AM
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RE: My 2300 only likes one prop
OK I seen this in a few places seems that everyone is under the impression that rotating the spray bar leans the engine out ,no matter which way its turned .My experience says that is not so!I went through the manual and cant find anything about it on the 2300.But I know it was mentioned in the other manuals for the G-90 and so on .Anyway for a engine that is running to rich in the midrange I turn the spray bar to wards the front of the carb, if its to lean I go the other way.I have always liked this third adjustment, it has let me dial in a engine to its max performance.
This is from SUPER TIGRE FAQ website.[quote][/qTo properly set up your carburetor, there are a few steps...
Make sure the spraybar is set so that the fuel slot is pointed straight down the center of the carburetor. You will have to look through the carb from the bottom, with the venturi opened to full. Loosen the two screws next to the high-speed needle valve to rotate the spraybar so that the slot is centered.
The idle needle can be seen in the slot of the spraybar. It looks like a piece of wire that has the end squarely cutoff. It should be less than one-half way across the slot when the venturi is opened to full.
The high-speed needle should be opened about 2-1/2 to 3 turns out from closed.
All of these settings are very rich. You'll have to start the engine at about 1/4 to 1/3 throttle. Once the engine starts, advance the throttle to full. You can then lean the high-speed needle until the engine is running just rich of peak RPM.
Once you have the high-speed needle set, you can retard the throttle a bit and use the idle needle to adjust the engine. Retard a bit, and adjust. Keep doing this until you have reached the desired idle RPM and mixture. Remember, since we started out with an intentionally-rich setting, the idle mixture will have to be leaned.
Finally, the midrange can be adjusted by rotating the spraybar a hair. Just loosen the two screws next to the high-speed needle and rotate the spraybar just a tiny bit. Either direction is OK. This will help you get a good transition and midrange.
I know this FAQ said 1.20 and under carb ,but the .61 to 1.80 is the same carb and they are the same as the .40 to .61 except for the fatter round spray bar.
This is from SUPER TIGRE FAQ website.[quote][/qTo properly set up your carburetor, there are a few steps...
Make sure the spraybar is set so that the fuel slot is pointed straight down the center of the carburetor. You will have to look through the carb from the bottom, with the venturi opened to full. Loosen the two screws next to the high-speed needle valve to rotate the spraybar so that the slot is centered.
The idle needle can be seen in the slot of the spraybar. It looks like a piece of wire that has the end squarely cutoff. It should be less than one-half way across the slot when the venturi is opened to full.
The high-speed needle should be opened about 2-1/2 to 3 turns out from closed.
All of these settings are very rich. You'll have to start the engine at about 1/4 to 1/3 throttle. Once the engine starts, advance the throttle to full. You can then lean the high-speed needle until the engine is running just rich of peak RPM.
Once you have the high-speed needle set, you can retard the throttle a bit and use the idle needle to adjust the engine. Retard a bit, and adjust. Keep doing this until you have reached the desired idle RPM and mixture. Remember, since we started out with an intentionally-rich setting, the idle mixture will have to be leaned.
Finally, the midrange can be adjusted by rotating the spraybar a hair. Just loosen the two screws next to the high-speed needle and rotate the spraybar just a tiny bit. Either direction is OK. This will help you get a good transition and midrange.
I know this FAQ said 1.20 and under carb ,but the .61 to 1.80 is the same carb and they are the same as the .40 to .61 except for the fatter round spray bar.