 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion Groups General ModelsRailroadsRocketsRadio Controlled Air ModelsHelicoptersLand ModelsWater ModelsModelGeeks.com Contact UsLink To UsSearch & Site Map |
Model Forum / Radio Controlled / Air Models / April 2009Super Tigre Carb Tuning
I am having a bit of a problem getting my ST 51 to run smoothly. I have had STs before so I know you have a delicate balance between the low end and high end before you get it just right. I recall reading somewhere that the position of the spray bar is very critical as well. Has anyone also heard of this? And what position would be ideal? Most engines like it pointed straight down but I seem to think the STs prefer a little upward thrust of the spray so if you are looking from the needle valve side it would be pointed around 4 o'clock. Any thoughts or experience on this? Many thanks. Ted >I am having a bit of a problem getting my ST 51 to run smoothly. I >have had STs before so I know you have a delicate balance between the [quoted text clipped - 5 lines] >the needle valve side it would be pointed around 4 o'clock. Any >thoughts or experience on this? Many thanks. I have no personal experience of tuning an ST. Their web site (and many other people who have posted here since 1995) recommends that the hole in the spraybar be straight down: http://www.supertigre.com/faq/product-faq.html As often happens with tuning, people disagree about what works and what doesn't work. In my view, you should feel free to experiment and report your results here so that the peanut gallery can learn from your mistakes. :o) Marty  SignatureBig-8 newsgroups: humanities.*, misc.*, news.*, rec.*, sci.*, soc.*, talk.* See http://www.big-8.org for info on how to add or remove newsgroups. >>I am having a bit of a problem getting my ST 51 to run smoothly. I >>have had STs before so I know you have a delicate balance between the [quoted text clipped - 21 lines] > > Marty ------------- Many folks, because of previous exposure to OS "no break-in" engines, attempt to fine tune and fly a Super Tigre engine long before it is ready to be put into service. These are the folks that end up complaining about those miserable ST carburetors. Marketing will not mention just how long an ST engine needs to be broken-in because of a possible loss of sales, so they let their customers bumble around making confetti of their models because of an improper break-in regime. All marketing cares about is profit. Not their customers' well being or enjoyment of their purchase. Super Tigre engines are fine engines, but none of them come ready to fly right out of the box, like OS. Trying to break-in an ST engine in the air, unless it is ABC, is pretty much a waste of time and nearly a sure bet to destroy your model, unless you are very experienced and are accustomed to deadsticks and their requisite landings. This does not make ST engines a bad buy. It simply means that one has to learn something new and employ a test stand for break-in. Once accomplished, an ST engine will last many decades of fairly rigorous use. Not done properly, the engine can be ruined in no time flat. Once the engine is broken-in, the carb that comes with ST engines suddenly changes into a pussycat to adjust and operate. Surprise! Ed Cregger >------------- > [quoted text clipped - 22 lines] >Once the engine is broken-in, the carb that comes with ST engines suddenly >changes into a pussycat to adjust and operate. Surprise! >Ed Cregger Ed: In your estimation, Does this apply equally to the new oriental ST engines as to the older ones Italian manufacture? bob >>------------- >> [quoted text clipped - 38 lines] > > bob I'm not Ed but I concur with what he said and I have a newer ST45 and it took some breaking in and now is much better. mk >>------------- >> [quoted text clipped - 38 lines] > > bob ------------ Bob, I suspect that the Chinese are making the engines a little better, or they have switched to softer metals, because I have heard that the newer Chinese engines take a little less time to come in on the average. I have no scientific proof of this at all. But lots of folks are reporting, via the web, that the engines, while not as readily broken-in as OS, are better in this respect than they were back in "the old days". I'm not knocking Italy's Super Tigre's efforts either. CNC machinery hasn't been around all that long, so the Italians may not have been set up as well in this regard as the current Chinese manufacturers. These are simply my impressions and nothing more. Ed Cregger >>>------------- >>> [quoted text clipped - 57 lines] > > Ed Cregger This last ST45 I bought woud NOT turn over by hand when I got it. I added oil and rotated it without a glow plug until it got better. It's one of the higher RPM ST45s at the club now.(we race 'em) mk ED -- Here in Florida we've been running the ST .40s in a Club 40 Pylon Race program, having switched over from the OS .40LA. Most of the racers are running the STs in for a few tankfulls before flying. Other than a few deadsticks, these new engines seem to be OK with an in-fight break-in. Most fly with a smaller prop than what they will race with, and certainly do not run the lean at any time. After a while, no one is having and problems. We supply 15% Cool Power fuel and most of the guys are happy with an OS #8 plug. Cheers -- \_________Lyman Slack________/ \_______Flying Gators R/C___/ \_____AMA 6430 LM____ / \___Gainesville FL_____/ Visit my Web Site at www.LymanSlack.com >>>Super Tigre engines are fine engines, but none of them come ready to fly >>>right out of the box, like OS. Trying to break-in an ST engine in the [quoted text clipped - 12 lines] >>>suddenly >>>changes into a pussycat to adjust and operate. Surprise! >>>Ed Cregger > ED -- > [quoted text clipped - 6 lines] > problems. We supply 15% Cool Power fuel and most of the guys are happy > with an OS #8 plug. ------------------ Running a smaller prop would let the engine run cooler when wide open. That might be helping the situation a bit. The GS-40 engines that I have seen rev up really well. Frankly, I didn't expect anything nearly as dramatic in power production. They are still one of the best buys in R/C. Ed Cregger I have the best luck with "Tiger Fuel" which is lower in nitro and oil than the typical 15% coolpower, etc. fuel. But then I have been running bigger Tiger engines too! > ED -- > [quoted text clipped - 33 lines] > >>>>Ed Cregger >I have the best luck with "Tiger Fuel" which is lower in nitro and oil than >the typical 15% coolpower, etc. fuel. But then I have been running bigger >Tiger engines too! Just don't mistakenly burn it in the smaller engines and tune them the way that most folks do. Smoke city. Ed Cregger Makes sense. The Chinese metallurgy ain't that great! >>>------------- >>> [quoted text clipped - 57 lines] > > Ed Cregger > I am having a bit of a problem getting my ST 51 to run smoothly. I > have had STs before so I know you have a delicate balance between the [quoted text clipped - 7 lines] > > Ted Start with the spray bar straight. It may take a tiny twist later but that is usually your last resort. The most important thing you can do, in particular with the ST51, is switch to an OS-8 glow plug. The ST plugs are basically junk. I fought with my ST51 for months before I came to that simple solution. It simply wouldn't mid-range well. Now it runs great, hardly ever needs adjustment, and starts easily. Good luck, --Mark Like you, several years ago I went NUTS trying to get a ST to run right. Here is what I learned the hard way: DON'T MESS WITH THE SPRAYBAR POSITION FRO THE FACTORY! The secret to getting an ST to run right is as follows: 1.Start and adjust for high end mixture. Stop engine. 2. Connect a piece of fuel line to the carb that is long enough you can put the other end in your mouth to blow through. 3. CLOSE the idle mixture needle. 4. While blowing into the fuel line, open the idle needle until you can JUST hear air coming through. 5. reconnect fuel line and start engine. Adjust high end needle again. You are done. This will normally set up the carb nearly perfectly and allow transition from low to high throttle without the 'stumble'. Good luck! >> I am having a bit of a problem getting my ST 51 to run smoothly. I >> have had STs before so I know you have a delicate balance between the [quoted text clipped - 18 lines] > Good luck, > --Mark >I am having a bit of a problem getting my ST 51 to run smoothly. I > have had STs before so I know you have a delicate balance between the [quoted text clipped - 7 lines] > > Ted A couple of weekends ago we took apart a ST45 carb. Seems to me(<-that was a disclosure about accuracy), the spray bar was at 4 or 5 o;clock when viewing it from the needle end. It looked to be pointing right down the throat of the engine. I have one I could go take apart and look at if ya want? Use an OS #8 mk > I recall reading > > somewhere that the position of the spray bar is very critical as well. [quoted text clipped - 11 lines] > throat of the engine. I have one I could go take apart and look at if ya > want? Use an OS #8 ST carb spray bars like to be pointed straight back towards the cylinder head. Signaturem-m >I am having a bit of a problem getting my ST 51 to run smoothly. I > have had STs before so I know you have a delicate balance between the [quoted text clipped - 7 lines] > > Ted The spray bar position is considered to be a tuning adjustment also. In my club we would swap the ST carb for an OS. Then they would run like a raped ape. >I am having a bit of a problem getting my ST 51 to run smoothly. I > have had STs before so I know you have a delicate balance between the [quoted text clipped - 5 lines] > the needle valve side it would be pointed around 4 o'clock. Any > thoughts or experience on this? Many thanks. Is it a true 2 needle carb, and not a high speed needle and air bleed valve? If the spray bar changes do not do the trick, and it is a two needle carb, you might be able to take a trick from the older Fox engines. The instructions told the user to modify the profile of the low speed needle to adjust the midrange. The told you (and they were right) to chuck it into a drill, and turn it fast, and put some sandpaper to it, either on the tip to "dull it" or the "shoulder" where the angle met the full diameter of the shaft. I think (it has been a while) if the midrange was lean, you sand a small radius on the shoulder. It does not take much, and if you go too far, be prepared to buy a new needle and try again. DAMHIKT! <g> SignatureJim in NC Hi Ted, My experience with the 5 ST engines that I have owned/own has been varied. I have never experienced that moving the spray bar has made a difference in the performance of the Super Tigre engines. I have also tried placing a brass ferral in the carb throat to decrease the intake diameter with no positive effect. Today I have two G-51 that are three years old and they both misbehave on a regular basis. One is on a Seamaster and I have the low needle at 8 plus turns out to keep the low end and mid transition from going lean. The other G-51 is on a trainer and is always full of surprises. I don't know if these engines are sensitive to barometric pressure or the alignment of the planets. Some days they run very acceptable and other days they are threatening to stall during transitions. I have a G-45 and a 40 (Italian made) that run like clocks with no issues what so ever. I did own ( and now returned to Tower Hobbies with full refund) a 61 size engine that ate three planes. I see others peoples responses indicate that they need a lot of break-in. If more that three gallons of fuel does not qualify for break-in, then I need to sell these G51's to some unsuspecting person on Ebay and go buy some magnum XLS-46's. I have not replaced my temperamental ST G-51's because I am frugal and I like a dead stick challenge at least twice a week. If I were to purchase new engines I would not purchase a ST again. I own OS, GMS, Magnum, Jett and Weston engines and do not have the trouble that I have with the two G-51's. On a side thought, maybe the issue with the G-51's are a quality issue with machined surface tolerances and are on the margin of acceptable dimensions. Does anybody know what happens when the crank intake area under the carb opening and the inside wall of the crank case get leaky? Thanks for reading RCS >I am having a bit of a problem getting my ST 51 to run smoothly. I > have had STs before so I know you have a delicate balance between the [quoted text clipped - 7 lines] > > Ted > Hi Ted, > My experience with the 5 ST engines that I have owned/own has been varied. [quoted text clipped - 44 lines] >> >> Ted ------------ I'm going to treat this subject as though there are folks reading my response is brand new to the hobby - not you. The first thing I would do is to compare the ST.51 engines' features to those of the engines you own that run well. Are they ringed? The ST.51 is a ringed engine. Are you using the same glow plugs in all of your good running engines and is this the same type of glow plug that you are using in your G.51 engines? Fuel? Prop sizes for equal and near displacements? Inverted engine installation? Can you see where I'm going with this? I realize that you have probably already been through this routine, so forgive me for being simplistic, but many times the things that are causing us grief are simplistic. If your other ST engines are running great and are nearly the same size, might not their carbs switch with your problematic .51 engines? Might be worth a try. A ringed engine can have quirks in running that are caused by a defective ring, or a defective ring slot in the piston. Changing a ring and inspecting the ring slot/groove is an easy process and is one that might yield an answer to your problem. I can think of nothing about the ST.51 design that is problematic on a regular basis. I am not telling you that I don't believe you or that you are hallucinating. I believe you. Let's get to the bottom of this. Now it is time for you to answer some of the above questions, if you please. Ed Cregger >> Hi Ted, >> My experience with the 5 ST engines that I have owned/own has been [quoted text clipped - 77 lines] > > Ed Cregger Mr Ed, Hopeflully this information will satisfy your curiosity. I have replaced the stock carb with a perry carb with no improvements. I did replace the ring in one of the two engines with no improvement. I buy plugs a dozen at a time and all of my 2 cycles have the same plug. All of my 2 cycles that I own use the same 15%N 20% synth/castor mix fuel. I have an 10.5 x 6 on one engine and a 9.5 X6 on the second. These engines were purchased within 6 mos. of each other 3 to 3.5 years ago. I'm done with the one. If you would like, I'll ship it to you. If you fix it, let everyone know what I did not do to get the engine to run satisfactorly. thanks, rcs >>> Hi Ted, >>> My experience with the 5 ST engines that I have owned/own has been [quoted text clipped - 93 lines] > thanks, > rcs ------------- There have been a lot of posts through my mind since your original post, so pardon me if I get confused with the particulars of your situation. All of the props you listed are small for an ST .51, so I assume that you are trying to go really fast with this engine. Frankly, picking a large displacement version of an engine that was built in a smaller engine's crankcase was not the best move. Notice how heavy the Rossi .45 engines are? That's because they carry more metal in their cases, metal that can be removed to form larger bypass passages. The larger bypass passage permits the Rossi to breathe better and produce more power. Usually at a very high rpm. If you read some reviews, you'll notice that folks are not generally as happy with the .53 sized Rossi either and for the same reason as the .51 Tigre. The larger displacement engines should be used to carry more prop and conventional rpm levels and not used for very high rpm engines. My choice, had I wanted a Super Tigre to go fast in that size range, would have been for the .45 ABC. It would have been a better engine for high rpm operation than the .51. Sorry if I'm completely disconnected from this thread. Thunderstorms in the area mess with this old man's noggin. Thanks for the offer of sending it to me. That was nice of you, but I'm very busy with my recording studio (amateur), motorcycle and ham radio. Flying is being relegated to very small glow and electric models these days. Good luck on your next choice of engine. Ed Cregger Can you provide me some basic instructions on tuning my smaller (les than 120 sized) SuperTigre carburetor? To properly set up your carburetor, there are a few steps... Make sure the spraybar is set so that the fuel slot is pointed straigh down the center of the carburetor. You will have to look through th carb from the bottom, with the venturi opened to full. Loosen the tw screws next to the high-speed needle valve to rotate the spraybar s that the slot is centered. The idle needle can be seen in the slot of the spraybar. It looks lik a piece of wire that has the end squarely cutoff. It should be less tha 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 fro closed. All of these settings are very rich. You'll have to start the engine a about 1/4 to 1/3 throttle. Once the engine starts, advance the throttl to full. You can then lean the high-speed needle until the engine i running just rich of peak RPM. Once you have the high-speed needle set, you can retard the throttle bit and use the idle needle to adjust the engine. Retard a bit, an adjust. Keep doing this until you have reached the desired idle RPM an mixture. Remember, since we started out with an intentionally-ric 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 th spraybar just a tiny bit. Either direction is OK. This will help you ge a good transition and midrange -- bgferr How old is your Super Tigre engine? The older series of ST carbs tuned like a recent OS and did not need midrange adjustment of the spraybar unless you were running a tuned pipe. Sometimes not even then. Ed Cregger > Can you provide me some basic instructions on tuning my smaller (less > than 120 sized) SuperTigre carburetor? [quoted text clipped - 28 lines] > spraybar just a tiny bit. Either direction is OK. This will help you get > a good transition and midrange. > How old is your Super Tigre engine? The older series of ST carbs tuned > like a recent OS and did not need midrange adjustment of the spraybar > unless you were running a tuned pipe. Sometimes not even then. > > Ed Cregger I have around two dozen Super Tigre engines and I don't think I've ever made the famous spraybar "midrange adjustment." I think Super Tigre's hard-to-tune reputation is undeserved and intimidates some folks. Good flying, desmobob >> How old is your Super Tigre engine? The older series of ST carbs tuned >> like a recent OS and did not need midrange adjustment of the spraybar [quoted text clipped - 10 lines] > Good flying, > desmobob -------------- Agreed. The problem, as I see it, is that folks plop a NIB engine on a model and expect it to be able to tune it right up and just fly. That's not how many glow engines work right out of the box. There is that necessary thing called break-in. Many brand new engines are not reliable in idle and transition until they have had at least four or five full tanks of fuel rank through them and even then they will improve significantly over the next twenty or so tanks of fuel and will require retuning now and then. Then to further exacerbate the "problem", folks fit the engine with a 12" low pitched propeller, which compounds the problem and makes an engine that is designed to run on 10" props struggle with swinging a huge windmill. Super Tigres were designed to rev up. The standard prop for a .40 to .45 back when these engines were designed was a 10x6 or 7, NOT an 11x6 or a 12x4 - 5. Wanna make it even worse? Use fuel with 15% or more nitromethane. Suddenly we have a midrange that is too rich, so what do we do? We use an OS Type F glow plug which ratchets up the problem even more. OS Engines has followed these usage trends by designing engines with extra large cooling fins and more of them. The result is that these engines will tolerate larger propellers and greater amounts of nitro without a problem. To even make it better yet, their machining specs are so much tighter that their engines really do not need an old fashioned break-in. Just the token break-in described in the instructions. Gee, now I feel better that I have a couple of OS .55AX engines. Maybe, after completing a few sales and swaps to help clean out the garage, I'll be able to resurrect my Fun One and plop one of the .55AXs on the Edson Universal Adjustable Engine Mount that I bought from MECOA/RJL a short while ago. Ed Cregger It's a new GS 40 made in China not Italy. The info on my previous pos is straight from the FAQ section of the Super Tigre website. I have ye to try it, but I will soon as I am having issues on the transition fro idle to wot -- bgferr Fit it with a 10x6 prop and burn fuel with no more than 10% nitro. Run four or five tanks of fuel through it on the ground, but elevated three feet, very rich to seat the ring. Keep running the 10x6 or even a 9x6 or 7 sized prop. Don't fall for the 11x6 thing that folks will tell you to use. The Super Tigre .40 was designed in an era of high revving engines - noise be damned. If you try to lug them down with a large prop, you will experienced a rich midrange, even after break-in is complete. The GS-40 is a great engine. Congratulations. There is nothing wrong with the carb. Ed Cregger ------------- > It's a new GS 40 made in China not Italy. The info on my previous post > is straight from the FAQ section of the Super Tigre website. I have yet > to try it, but I will soon as I am having issues on the transition from > idle to wot. There is a premium plug from Enya that solved the midrange barbling when accelerating from idle to takeoff. After dinking (n optional) around with two ST51's from the 90's I found the extra buck or two for the premium plug to be the permanent fix. Went from deadstick dog to reliable. Frank Bowman, a piston ring fitting guy who I no longer seem to be able to contact, clearly stated to me in an email that he religiously laps the liner tops on Super tiger liners that he is fitting rings to. He said that they are notorious for not being flat enough to seal properly at first. Perhaps the "extended break in" is the period of time to gum up the leaky head? I've seen more than one exhibit "mystery" drops of fuel and oil coming off near the head gasket level. But the Enya #3 has higher platinum content- most of our "platinum" filaments in glow plugs are a sponge impregnated with a little platinum. The platinum is the magic which catalyzes the glow fuel to "compression ignite". One theory for why the enya 3 works so well is that it has more platinum for much longer. Sure they're $6 instead of $4, but mine all last for years. SignatureWaterbug Ted, point needle spray bar hole back toward engine cylinder 4or5 o'clock is fine as is straight down on some engines. 1)SET HIGH SPEED NEEDLE FOR LEAN RUN HOLDING AIRCRAFT NOSE UP AT A 45 DEGREE ANGLE. 2) open needele a couple of clicks. 3) AT LOW THROTTLE THROTTLE BARREL SHOULD SHOW A GAP ABOUT THE THICKNES OF A PIN. 3) ADVANCE THE THROTTLE STICK FOR MORE RPM WITH ENGINE RUNNING. IF THE THROTTLE STICK REACHES FULL SPEED BUT ENGINE SPITS AND SPUTTERS BUT THEN GOES ON TO O.K HIGH SPEED, THE LOW SPEED NEEDLE NEEDS TO BE CLOSED ALITTLE . USE VERY SMALL AMOUNTS OF TURNING NEEDLE HERE, TRY AGIAN. 4) IF THE ENGINE QUITS BEFORE YOU GET TO FULL THROTTLE STICK YOU NEED TO OPEN THE LOW SPEED NEEDLE. EASY DOES IT IT MAY TAKE A FEW TRYS. RE ADJUST THE HIGH SPEED NEEDLE AGIAN. REMEMBER THERE ARE 2 WAYS TO SLOW AN ENGINE DOWN AT LOW THROTTLE . ONE IS TO OPEN THE LOW SPEED NEEDLE TILL IT SLOWS DOWN. WRONK- WRONG -WRONG. CLOSING DOWN THE THROTTLE BARREL WILL GIVE LESS AIR THEREFORE A RICHER SLOWER MIXTURE. LIKEWISE OPENING THE GAP AT LOW SPEED SETTING WILL LEAN THE LOW SPEED MIXTURE. THE ABOVE PROCEEDURES IS THE SECRET TO THE BALLANCE YOU SEEK. SOME ENGINE CARBS JUST HAVE A BAD MID RANGE. THERE ARE FIXES FOR THIS IF TAFTER EXPERIMENTING WITHTHE ABOVE INFO THE CARB BARREL CAN BE WORKED ON. THAT TAKES AN OLD MODELER MACHINIST TO DO IT. . PS WHAT NITRO FUEL ARE YOU USING. YOU ARE USING AN IDLE BAR GLOW PLUG RIGHT? GOOD LUCK THE OLD MODELER >I am having a bit of a problem getting my ST 51 to run smoothly. I >have had STs before so I know you have a delicate balance between the [quoted text clipped - 7 lines] > >Ted |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2012 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.