RE: My 2300 only likes one prop
 

To tell you the truth, I don't really like the 7D carb. It has a funny low end adjustment that has limited range. The ST carb has two needles which will yield infinite adjustment. Mechanically, the 7D is very good, and it does run well. Mine is the remote needle version, which may be harder to transfer to the 2300. I'll look into switching it over and do some ground runs to see if I can tell any difference. I think I should go back to the stock muffler for all tests involving the carb.

If by chance the 7D does fix it, I will be disappointed. Replacing a carb on a new engine to get it to function is not acceptable by my standards. It would prove to me that the engineering at SuperTigre is lacking, and they are selling a product that should be improved before it hits the market. I honestly hope it runs similar with the 7D, then I can look elsewhere for the problem.

RE: My 2300 only likes one prop
 

not24 if you are running the lower nitro content you are probably leaning the high end needle out and maybe even overheating the motor. Higher nitro burns more efficiently without the need to lean the top end out. The combination of glow to fuel could have something to do with this but hopefully you have made subtle changes each time you have tried something different. big changes equal big results. It is easier to go back to the previous setting if it is done in moderation. I run on my 2300 a os f type plug. 15% nitro and minimal 18% oil. It will idle as good as any os motors I have and the transition is good to full power. I do not play into too much mid range. if it is a little rough through the mid range that's ok. Who really flies at half throttle through their routine? Most drop engine rpm on the down side and increase through the level or up lines. inadvertently leaning out to a comfortable range. Try tuning the high end level not with the nose straight up. Then come down rich 2 to 3 clicks. This will ensure preventing overleaning on your straight lines and keeping enough fuel draw during the times your motor is heating up the most especially vertical. Try a fresh plug and starting at the out of the box orientation for your needle. Given that all the nuts and bolts are tight and your not losing any seals your pressures inside the motor should maintain it's performance. I am very happy with mine. I run a 17x8 apc with 15% omega fuel and f type plug. I keep it just a hair rich. Runs at 9300 rpms Not one DS landing yet.

RE: My 2300 only likes one prop
 

Not 24,

I am like you and hate to replace anything on a brand new engine[:o] and I realy like the st engines.
I have some thoughts and drawings about how to fix the st carb. maybe I can upload them here later today.
Change only one thing at a time! I would say change the carb first and go fly and only if you have fueldraw problems then change to the stock muffler.Otherwise you wont know what solved the problem.

RE: My 2300 only likes one prop
 

Hi again,

These are some drawings I have done. The first picture is the spraybar as it comes stock without any modification and the second picture is how I think;) it should look like after the modification for good midrange. Maybe a very sharp knife is enough to grind out the material and get the job done?

RE: My 2300 only likes one prop
 

I appreciate all the different responses to this issue. Keep in mind that I can only fly one day per week, usually Sunday, so sorting this thing out will still take some time.

I would bet my Corvette that I am not running the engine lean on top. I have excessive smoke trail that leads me to believe that I'm actually on the rich side. I lean the engine with a tach, and have to back out more than 1/2 turn from peak to get a 200 rpm drop. Seems like the high needle has exponential. While leaning the high needle, rpm picks up very slowly till it just falls off on the lean side very rapidly. So when richening from peak, it takes quite a bit of needle travel to see a change on the tach. My OS carb on the 1.08 is sensitive to + or - 1 click on the high needle. This engine is pumped, and that made a difference. I'm thinking that pumping the 2300 might have the same effect on the needle sensitivity. Backing off the muffler pressure will reduce fuel pressure, and make the needle even less sesitive. Another fact that makes the pump look like a step in the right direction. With the pump, I can run an unrestricted exhaust, which will remove the "too much backpressure" variable from the equation.

RE: My 2300 only likes one prop
 

NOT24 Super tigres don't like high nitro. 0-10% SUPER TIGRES are hard to set carb by ear. They will keep running lean on high end. Some brands of engines a couple clicks lean will kill engine ,not ST . Plenty of smoke on lean means your hot burning the oil instead of spitting it out. Best luck is set HS with tach slowly find top RPM and then richen 400 RPM Make sure to hold plane straight up for 10 seconds. Low end -do pinch test adjustments less than 1/8 turn. If you turn more you will go past sweet spot sometimes. Run your 18x6 for 9,000 range. Stock muffler has enough pressure . Some pitts need one of the outlets plugged. Plugs FOX MIRICLE ,OS F ,FOX IDLE BAR, OS 8 Make sure your carb doesn't have chunk in it. I just back blew a carb out and got a plastic chunk out of line. Engine would sometimes go to 1/2 RPM struggling to get fuel. Go down to idle and then to Full RPM .

RE: My 2300 only likes one prop
 

1/2 turn to drop 200 RPM on HS is telling you your low speed needle is out of whack. Get your lowest reliable idle and pull fuel line. you should hear a slight RPM increase before it dies. If it runs on for more than a second your way to rich. I,ve seen some peoples engine run for 5 to 15 seconds with fuel line off and they said it was set perfect. If it dies instantly it is too lean. You always have to set HS after you set LS.

RE: My 2300 only likes one prop
 

Please see our note on adjusting the carb of your SuperTigre G2300 in the SuperTigre Support Forum. You must start out with the top-end and idle set much to rich. Start at part throttle and get to full throttle. Then lean the top end first. Once it's found, you can lean the idle mixture and get the idle RPM set. Many people try to idle the engine too slowly. That can cause problems with acceleration and operation in the midrange. We consider anything below 2,500 as "good".

RE: My 2300 only likes one prop
 

I did some mods to my setup with the 2300. I relocated my throttle servo so I can put the tank about 2" closer to the engine. I mounted the engine inverted. I installed the stock muffler. I'm still running large fuel line, F plug, and 10% powermaster. I ran the 18-6 prop, the one that wouldn't run before.

I was seeing 9100 peak and 2600 for a reliable idle. The low needle is still very sensitive, but I believe I have it set perfectly. I can idle for 30 seconds and punch it, with only excessive smoke, but no bogging. I can also hold the model vertical at 5000 rpm without it leaning out and sagging.

I haven't flown it yet, but I believe it will do fine. I like the sound of the stock muffler better than the Bisson pitts. Spool up is lazy, but that can be fixed easily by going to a wooden prop.

The only issue I have is that fuel siphons into the carb because of tank placement. As long as I start it right away there is no problem. It may go lean on me when I fly inverted or do outside maneuvers. I had to mount the engine inverted to get the muffler to clear the engine box without hacking it up.

Now I wait for the weather to cooperate and I'll see how she does.

RE: My 2300 only likes one prop
 

Consider converting your fuel tank to a uni-flow. You can do this by putting a clunk on your vent line--just make it shorter than your pick up line so you do no intake air bubbles.

9100 with APC 18x6w is very good. Should pull very hard.

RE: My 2300 only likes one prop
 

Mine would always do this a the field too, but in the air there are more variables to consider.

RE: My 2300 only likes one prop
 

I have made significant progress, because I did have flameouts on the ground before with that prop. Now it runs on the ground as well as any other engine. I think it will do fine.

RE: My 2300 only likes one prop
 

Nt24 did you try out your latest adjustments to the 2300? How did it fly? I have the same motor and interested on how it did.

RE: My 2300 only likes one prop
 

I have never heard of this before. Can you please explain this concept? With the engine inverted, fuel drips out of the carb, but it can't flood the engine because the carb is upside down. It's not necessary to prime the engine, just connect the battery and give it a few flips.

I'm using cheapo Master Airscrew classic propellers. They are a little more durable than the APC's and a lot cheaper. I will eventually go with a Pro Zinger, once I find what size I really like. I'm thinking 17-8 or 17-10. I like the good pull at lower revs with the higher pitch. Even with the 18-8 I have to drive the plane to the runway with power, when I throttle back it's like putting on the brakes.

By the way, with the cg moved fwd the plane flies really nice. The extra power makes it feel much more confident in the air. I haven't measured to find where the cg is, but it takes a little down while inverted. Landings are much more manageable. Flies like a big sport model, but does really nice rolling circles and wicked rolling harriers. A real joy to fly.

RE: My 2300 only likes one prop
 

Havent had the chance to fly it since moving things around. I'm still trying to get things right without using a fuel pump. Even though this engine is on a Funtana 90, I'm not really into the 3D thing that much. The carb seems to be as good as any other carb I have run. Seems that the sticky point with this engine boils down to correct tank placement and fuel tank pressure from the muffler.

At this point I would say that the engine is an excellent buy for those wanting lots of power for a little money. For any flying other than hardcore 3D it will hold it's own with the others. I am still learning this engine, and perhaps I will discover the right setup that makes this engine 3D capable.

RE: My 2300 only likes one prop
 

I think its a High speed needle flow thing, not sure how. The engines on all my planes are either sideways or inverted. If the tank was higher on them, I could not tune them at all. I don't see how flooding can happen. So lets say the tank is lowered and you have a pump or regulator, then why doesn't the same thing happen? Beats me. What I do know is I have my engines mounted in the worst case scenarios and if the tanks are lowered , they run perfectly and no issues at all.

RE: My 2300 only likes one prop
 

Fuel dripping out the carb is no big deal to me. I can either pinch the fuel line or close the main needle till I'm ready to start the engine. It seems to run the same as it did when it was mounted sideways. It actually looks better inverted, even though the cowl is still off.

If I were to move my throttle servo one more time I could probably lower the tank another 3/4", which may be just enough to stop it from siphoning. I was in a hurry, and didn't have another throttle pushrod handy. I had moved the throttle servo forward with the lighter engine. Now I could move it back near where it was.

If the engine has fuel draw problems at low rpm's, my next trick is to sleeve the carb barrel to try to increase the vacuum in the venturi. Then, perhaps, tank placement and muffler pressure won't be as critical.

RE: My 2300 only likes one prop
 

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When your tank is at the proper height and your model has tricycle gear, it is not uncommon to have to use forceps to block off the fuel line lest half a tank of fuel drains out of the tank and into your engine or on the ground. This is the price we pay for using suction fed carbs. Lowering the tank to prevent this will sacrifice good performance for convenience. Forceps are cheap. The real trick is to not fill the tank until you are going to fly. No forceps are needed then.

My G2300 runs fine without a sleeve. Fine needle adjustments are needed in order to dial it in to where it will run properly. I've seen flyers tune their engines with nothing less than 1/2 rotations of the needles. Doesn't work well that way.

My G2300 runs just fine with the stock carb on 5% nitro standard model fuel. I use the OS Type F glow plug. The latter helps immeasurably.

RE: My 2300 only likes one prop
 

Not24 When you do the upright test. You want full throttle to see if your getting enough fuel for unlimited vertical. 5,000 RPM is not enough. If your fill is a T or third line you will get alot more carb drippage and flooding than using an outside line fill . Thats because you pull the line off that goes to carb and your fuel only goes to tank. If your carb is lower than tank you will get drippage. Ideal is center of tank is level with center off carb.

RE: My 2300 only likes one prop
 

With my current setup, both needles are more sensitive, with the low speed being extremely touchy. I can almost set the high speed by ear, but I still use a tach. The low speed adjustments are the smallest movement of the screw that I can make. 5 degrees of rotation makes a difference, and 15 degrees is a lot of adjustment. I fine tune it with these small adjustments.

RE: My 2300 only likes one prop
 

Refer to the above post. The high end needle is set first, and if it's done properly, the vertical test will show a slight increase in rpm. Adjusted 400 rpm rich of peak works well for this. The reason I do the low speed needle vertical test at 5000 rpm is this. When the low speed is lean enough to give good idle, no flooding, and no hesitation, it is too lean to go vertically at low throttle settings. So I start at that nice lean setting, which is where you would think it should be, check the idle and transition and all seems well. Go to 5000 rpm and raise the nose. Goes lean and dies. I richen the low needle in very small incriments till I can do this test and have the engine run steady the whole time. It is possible to be rich enough to get an increase in rpm when you do this, but that setting runs noticeably rich at idle. Notice that the difference in the low needle setting may only be 1/8 of a turn from the starting point to where it runs vertically. I like the fact that this engine is that easy to adjust. Because I am so overpowered in the Funtana, I need to be able to run low power settings in all flight attitudes. I only use full throttle when going vertical. Other than that, the throttle is below half.

P.S. This is the only engine I have ever adjusted this way. I'm dying to try this method on some others.

RE: My 2300 only likes one prop
 

With the system I described above you would want your vent line to run above the tank so the fuel has to climb & overcome gravity in order to run out and start a siphon when filling.

By sinking the vent line pick up to the bottom of the tank (now same level as the fuel pick up) the positive pressure on the fuel pickup line is now removed or equalized--If the pick-up wants to start a siphon it has to overcome the pressure it takes to draw air down from the top of the fuel level to the bottom of the vent clunk. As soon as the motor starts to run the vent line is has positive pressure (from muffler and sucking of fuel) so there is no way fuel can travel out the vent.

If your vent clunk is too close to your pick up line there is a chance you could draw air bubbles and go lean--that is why I run my vent clunk shorter than my pick up clunk.

RE: My 2300 only likes one prop
 

Well, I got a flight in today. windy as hell, but I managed. Engine was a pain to start. Enough of a pain that I am definitely going to mount it either upright or sideways again. I also was reminded why I don't like stock mufflers. no matter how tight you screw them together, they fall apart in flight. Going back to the Bisson to solve that.

Now then. I have enough reasons under my belt to abandon the gravity feed fuel system and go with the pump. While the engine did stay running this time with the 18-6, it was still very inconsistent. It would go rich and lean in flight, depending on flight attitude and g forces. Full throttle vertical is out of sight. Much better than the 1.08 ever did. If all you want to do is fly around in circles and do an occasional loop or roll, the grvity feed system is fine. As soon as you try to wring it out a little bit, you get into trouble.

Some of you are saying "stay away from the vp30". I know, it's another variable to deal with. I'm ready for that fight to begin now. The engine is great, the fuel system is too tempermental without consistent fuel pressure.

RE: My 2300 only likes one prop
 

Are you going to start with the bypass?

RE: My 2300 only likes one prop
 

Yes, definitely. Just as you have shown in your diagram. It made a big difference in the 1.08, and I feel it will help the 2300. I think the carb is adjustable enough to work well, maybe even better than the 7D. I'll be putting the tank back behind the wing tube again to help with the cg shift. The plane requires a trim change in flight with the tank in the nose.

One question. Which line do you use to fill the tank? I would guess the best one would be #6.