RE: My 2300 only likes one prop (Full Version)

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STG -> RE: My 2300 only likes one prop (2/6/2006 4:27:35 AM)


quote:

ORIGINAL: Not24

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.


Yes, #6. I think it will work. Most say that the pump will not work with the 2300, but I bet the bypass system will. Keep us posted.




Not24 -> RE: My 2300 only likes one prop (2/7/2006 11:42:18 PM)

Got her running tonight on the pump. I tried two configurations. One is the bypass, and the other is direct. Amazingly, it seems to behave exactly like the OS 1.08 in both configurations with one exception. There is not enough fuel flow with the bypass to go rich on the high needle. This is similar to how it runs without the pump and the open muffler.

Let me talk about the direct system first.
With the pump as lean as it will go, I could richen and lean the high needle, and the low needle, but the midrange is excessively rich. That's the way the 1.08 runs. Definitely not flyable. I saw a peak of 8000 with the 18-8, and an idle of 1400 all day long. Just don't add power quickly, because it'll load up really bad, and never clears in the midrange.

The Bypass system works really well, but still needs one little tweak. The pump is set to full RICH, the high needle won't allow for slobbery rich, but will allow for finding peak and backing off a few hundred revs. The low needle acts just as it does without the pump. Idle is good, good as any I have seen, and will run forever at 2000 rpm. It will load up slightly if you do let it idle for a long time, but it is manageable with smooth throttle inputs. 15-30 seconds of idling won't load it up enough to be bothersome, and it definitely won't quit. The good thing about this setup is that the engine runs perfect from 3000 to 8000 rpm with NO BAD HABITS. Transition is perfect, and spool up is what I would call very good for such a heavy prop. Noticeably better than without the pump. It gets right on up to peak rpm within 1 second. Also, I can run the engine to 5000 and raise the nose to vertical and it won't lean out. Overall, a very flyable setup that is easy to tune. The pump is not even part of the tuning equation. Set it to full and forget it. I might also add that I did stretch the spring to 2X original length.

The only thing to play with now is to install a needle valve in the return line between the engine and the check valve. This will allow me to increase the pressure at the needle valve, making it possible to get it to go rich. It should also allow me to lean the low needle a little more, making for long idles with no hiccup on acceleration. This restriction was also required on the 1.08 to make the mid range rich enough. So, for all of those who still think the carb on the 2300 is not worthy, I say, so far it hasn't proven that to me.

The real test is in the flying. I'll report on that in a few days.

These pics are with the engine chugging at 2k.



STG -> RE: My 2300 only likes one prop (2/8/2006 12:06:09 AM)

Nice test stand.

Keep us posted on the needle valve in the bypass. I have thought about doing it(needle valve in bypass), but never have had to yet. It will be interesting to see how your low and mid react to more pump pressure at low rpm even with it leaned out.

Not sure if you are going to do this, but when you do your install in the plane make sure you get your "T" as close as you can to your needle valve.

Have you tried a cooler glow plug than the type "F"? You are running 10% with some castor correct?




Not24 -> RE: My 2300 only likes one prop (2/8/2006 12:13:42 AM)


quote:

ORIGINAL: STG

Nice test stand. Keep us posted on the needle valve in the bypass. I have thought about doing it(needle valve in bypass), but never have had to yet.



I'll just borrow one from the 1.08 for testing. The wheel collar is a little too chinsy for that purpose, but it does work.

By the way, I like flying with the 18-8 much better than the 18-6. It pulls more like a four stroke and doesn't sound like it's screaming all the time. 8000 rpm is very respectable. Initially, I only saw 7300 on that prop. I also have a 16-10 three blade to try someday.



buzzingb -> RE: My 2300 only likes one prop (2/8/2006 12:20:07 AM)

Not24, theres one thing I must say and that is you are one determined 2300 owner. That set up looks like a man in the recovery room after surgery. Keep up the good work and keep us posted.



Not24 -> RE: My 2300 only likes one prop (2/8/2006 12:26:25 AM)

Thanks, but it's really not that complicated. I made the stand in about an hour, and the plumbing is really simple. Two T's and a check valve, plus the pump. A picture is worth a thousand words. Can't wait to fly again!



Flyer95 -> RE: My 2300 only likes one prop (2/8/2006 8:13:51 AM)


quote:

ORIGINAL: Not24

Thanks, but it's really not that complicated. I made the stand in about an hour, and the plumbing is really simple. Two T's and a check valve, plus the pump. A picture is worth a thousand words. Can't wait to fly again!


Not 24,
Nice work[;)] Keep us informed about the running habits with the T and the check valve.



Not24 -> RE: My 2300 only likes one prop (2/9/2006 12:46:08 AM)

I borrowed the needle valve off the 1.08 and installed it in the bypass line. It was extremely difficult to get the engine to start, and tuning was a nightmare. That needle controls the fuel pressure, so if you move it, it screws up both the other needles, making tuning extremely exaserbating. I'm going to pass on the needle in the bypass line and go back to the setup in the pictures. To get the high end to richen up, I have two remaining options. I can drill out the fuel nipple on the carb to allow a higher flow rate, and I can add some backpressure by pinching the muffler closed a little. Without having a pressurized tank, I don't know if the muffler actually has anything to do with fuel draw anymore, so I will enlarge the fuel nipple first.



STG -> RE: My 2300 only likes one prop (2/9/2006 2:40:11 AM)


quote:

ORIGINAL: Not24

I borrowed the needle valve off the 1.08 and installed it in the bypass line. It was extremely difficult to get the engine to start, and tuning was a nightmare. That needle controls the fuel pressure, so if you move it, it screws up both the other needles, making tuning extremely exaserbating. I'm going to pass on the needle in the bypass line and go back to the setup in the pictures. To get the high end to richen up, I have two remaining options. I can drill out the fuel nipple on the carb to allow a higher flow rate, and I can add some backpressure by pinching the muffler closed a little. Without having a pressurized tank, I don't know if the muffler actually has anything to do with fuel draw anymore, so I will enlarge the fuel nipple first.


quote:

The pump is set to full RICH, the high needle won't allow for slobbery rich, but will allow for finding peak and backing off a few hundred revs.


Why do you need your high speed to get richer than that if you are not trying to break in the motor anymore? Thanks for the info.

Have you tried to run your "T" closer to your needle valve? Have you tried a cooler glow plug?

Thanks for all your testing and reporting.




Not24 -> RE: My 2300 only likes one prop (2/9/2006 4:27:32 AM)

quote:

ORIGINAL: STG


Have you tried to run your "T" closer to your needle valve? Have you tried a cooler glow plug?

Thanks for all your testing and reporting.




I was thinking about trying that too, with the T being very close to the needle next time. I really can't see why it would matter, but I'll try it.

I'm having good success with the F plug. I have some a3's when it dies.

I was really disappointed in the way it ran tonight. I suppose you could tweak it in, but it would take many tanks of fuel to do it. Not worth it!



STG -> RE: My 2300 only likes one prop (2/9/2006 2:28:11 PM)

quote:

ORIGINAL: Not24

quote:

ORIGINAL: STG


Have you tried to run your "T" closer to your needle valve? Have you tried a cooler glow plug?

Thanks for all your testing and reporting.




I was thinking about trying that too, with the T being very close to the needle next time. I really can't see why it would matter, but I'll try it.

I'm having good success with the F plug. I have some a3's when it dies.

I was really disappointed in the way it ran tonight. I suppose you could tweak it in, but it would take many tanks of fuel to do it. Not worth it!


Moving the T closer to the the needle valve is just lessening the distance gravity can work against the correct fuel setting. I don't think it will change much on the bench, but in the air it might some -- especially since you have established that the pump is not over supplying the motor with fuel at higher needle settings(very open high speed needle).
--------------------
Have you seen this on glow plugs? As you know the A3 and TYPE F are very hot. Have you tried a cooler plug with the bypass(like a #8)? It may help you get a richer high speed and more power and economy.

I know everywhere you read the "F" plug is supposed to be the plug for the ST2300, but a lot of that has come from pattern fliers who mount the motors inverted, and with the glow plug straight down a hot F plug(that can stay lit as fuel pools on the plug at low settings) may be the only thing that could stop a flame out. The pattern fliers usually are running very low nitro levels(and thus hotter plug needed)

http://www.modeltechnics.com/glowplug/firepower.html

quote:

"Too cold a plug will cause loss of power and or poor throttling. TOO HOT A PLUG will also cause loss of power and or poor throttling..."

"FINE TUNE THE MIXTURE at maximum power. This not only increases the power further and improves the throttling but it can also increase the MILES PER GALLON BY UP TO 40%!"


I used to think that a hotter plug would help throttling in the bottom and mid range, but according to some sources if the plug is hotter than optimum then the needles need to be set richer to compensate. The richer mixture retards the timing to stop pre-detonation. And this richer setting actually can hurt throttling and more.

http://www.os-engines.co.jp/english/line_up/plug/pluindex.htm
quote:

Ignition timing is 'automatic': At higher rpm, the plug becomes hitter and, appropriately, fires the fuel/air charge earlier; at reduced rpm, the filament becames cooler and ignition is retarded.



Not24 -> RE: My 2300 only likes one prop (2/9/2006 10:05:05 PM)

Thanks for the links on glow plugs. I will get a new #8 and an A5. That should cover the whole heat range. Speaking of heat, it's too cold out there now to run that beast. It needs to be above 50 to keep me from freezing my hand off.

It will be interesting to see the different peak rpm's with the different glow plugs. I never paid that much attention to heat range before. Thanks for bringing it up.



STG -> RE: My 2300 only likes one prop (2/9/2006 10:12:39 PM)

quote:

ORIGINAL: Not24

It will be interesting to see the different peak rpm's with the different glow plugs. I never paid that much attention to heat range before. Thanks for bringing it up.


This is new to me also. It is nice to have a guy like you doing the testing for the rest of us. Thanks [8D]

At the very least you may gain better millage.



Flyer95 -> RE: My 2300 only likes one prop (2/11/2006 6:53:41 PM)

Not 24,
I have a ST90 and was out flying a few times today. The temperature was -8 celsius = 18Fahrenheit. I am also running a Perry VP30 and a muffled tuned pipe on it and the prop is a MA 16x7 prop peaked at 7600rpm. Plug is the OS-F and fuel is containing 10% nitro, one extra head shim is added. The carb is the mag108 carb restricted from 11mm to 8mm for the best fuel-draw. The engine ran very good[;)], quiet and powerful. The perry is installed per the instructions that came with it.



Not24 -> RE: My 2300 only likes one prop (2/11/2006 11:07:58 PM)

I have tried three or four ways to plumb the pump into the system, and what I have found is that the bypass system that STG and I are referring to is the most user friendly. When you have too much pressure to the carb, the midrange is very rich, and the low needle is much more touchy. The thing I like about the bypass system is that the pressure at the needle valve is increased over that of just muffler pressure, but not excessive, because it can bleed back to the tank. What you wind up with is consistent fuel pressure throughout the rpm range, and throughout the flight from full to empty tank. All mounting issues for tank position go away, and because you run the pump at maximum flow rate, even pump tuning is not required. Set it and forget it.



Not24 -> RE: My 2300 only likes one prop (2/15/2006 11:08:04 PM)

I have some tuning news to report on the 2300. I tried 5 glow plugs today on the test stand and believe it or not, there is no appreciable difference in max rpm with the different plugs. I used the following plugs:

F
A3
#8
A5
SuperTigre

Best performance was with the F, but the others were within 50 rpm. The worst running plug was the SuperTigre. There was no difference in the way the others ran. I saw 8000 rpm to 7920 rpm. Initially, I got 8200 on the F, but I checked each one twice, and the second run was 8000. Conclusions? The F plug is obviously not causing detonation with 10% fuel. The others may give up a little on idle. The ST plug is junk, and should be thrown away.

Next issue. The carb and pump setup.

Moving the T closer to the needle valve made no difference.

Having no control over bypass flow causes a lean high end needle that can't get into four stroke mode. Engine runs perfectly when held level, but raising the nose causes leaning. Setting it rich enough to run vertically is too rich for level.

Restricting bypass flow rate with remote needle valve will work, but causes hesitation on transition. Also causes high end to load up if bypass needle is closed enough to be able to run engine vertically.

My conclusion is this. The engine definitely benefits from the pump and especially the bypass system. However, the carburetor apparently is still lacking in engineering and /or quality. My advice to anyone with this engine is to either lower your standards and expectaions to a point that the performance of this engine is acceptable, or purchase a new carb with a better reputation for performance.

I have an ASP 1.08 carb and an OS 7D RN carb that I can try. I'll test the ASP carb first and report my findings. That engine is out of service, so the carb is available.




STG -> RE: My 2300 only likes one prop (2/15/2006 11:50:27 PM)


quote:

ORIGINAL: Not24

I have some tuning news to report on the 2300. I tried 5 glow plugs today on the test stand and believe it or not, there is no appreciable difference in max rpm with the different plugs. I used the following plugs:

F
A3
#8
A5
SuperTigre

Best performance was with the F, but the others were within 50 rpm. The worst running plug was the SuperTigre. There was no difference in the way the others ran. I saw 8000 rpm to 7920 rpm. Initially, I got 8200 on the F, but I checked each one twice, and the second run was 8000. Conclusions? The F plug is obviously not causing detonation with 10% fuel. The others may give up a little on idle. The ST plug is junk, and should be thrown away.



Sounds like you could use higher nitro fuel or more compression? [&:]

How about the needle valve setting with the cooler plugs? Could you lean it out more?

Thanks



Not24 -> RE: My 2300 only likes one prop (2/16/2006 12:15:01 AM)

I just bought a gallon of 5% Omega. This test was done on 10% Powermaster. I started the engine rich each time and didn't check the final max rpm settings. I can tell you that the high needle on this carb is where I think the real trouble lies. The 7D carb high needle has much more adjustment, whereas this carb's high needle is almost unnecessary. As I recall, the ASP carb is similar in that respect. The high needle is so bad that anything from 1.5 turns to 4 turns is about the same rpm. You can get it too lean, but never too rich. When you add fuel pressure to get it to go rich, it is way rich in the middle. Too bad for me, because I think a Perry carb is what this engine really needs. I have one on a .61 and it runs beautifully.



Cyclic Hardover -> RE: My 2300 only likes one prop (2/16/2006 2:13:50 AM)



Most people are oblivious to weather conditions along with altitude and the effect it has on engine performance. Any readings you get will most likely not be the same any two days in a row. When your at my altitude you pay attention to stuff like this because the numbers are an average of 17% lower than those in the seal level area. Clear days, cold days, humid days, hot days and the rest of it can give you a wide range of readings and the plug you have it does not matter.

I would not get to dependent on whatever it is your trying to accomplish, because it won't be the same tomorrow. Just find something that works and go with it.






Not24 -> RE: My 2300 only likes one prop (2/16/2006 2:28:41 AM)

What I am trying to accomplish is to determine weather or not the ST2300 is a good engine and has a good carb on it from the factory. If that is not true, then what does it take to get it to run properly. I'm trying to help others that may own one or are thinking about buying one. I'm exploring all the possibilities for getting this engine to run with the stock carb, so that it really is a good bargain. I think it can be made good enough to fly, and fly well, but to get the most from this engine, I think a replacement carb is in order. I am reluctant to admit that this is the case, but that is what I believe after all the fuel I have put through it on the ground and in the air. It pulls strong and swings a big prop well. I like the engine, but it can be made better. It is limited right now because of the carb. I will pursue this issue to its end, and post my findings, for the sake of those who don't have the time and resourses to experiment like I do.



buzzingb -> RE: My 2300 only likes one prop (2/16/2006 3:35:39 AM)

Not 24 why not give in and purchase a $75 Jett carb and give that a try?



Not24 -> RE: My 2300 only likes one prop (2/16/2006 3:51:29 AM)

quote:

ORIGINAL: buzzingb

Not 24 why not give in and purchase a $75 Jett carb and give that a try?


Not yet!!!!!!!! I have one more trick up my sleeve before I give up on this carb. I was just looking at the ASP 1.08 and noticing the diameter of the throat. It's much smaller than the st. Got to looking at the st carb again, and noticed the shape of the throat. It has a venturi effect downstream of the spraybar. This is okay. The problem is the hole in the carb barrel is larger than the hole in the carb body, meaning there is a big step as you go from body to barrel and back to body. I believe this may be the cause of the lethargic high speed needle. It's not that it's getting too little fuel, but rather way too much air. I'm going to make a sleeve that fits into the carb barrel to choke it down to the same diameter as the carb body. It doesn't matter how much air can flow through the carb if you can't get the mixture right. Cutting off some air should allow me to run the engine at more like 1 to 1.5 turns open, and also allow the engine to get slobbery rich when opened up. This is not my idea, but after the testing I have done, it makes perfect sense that this should solve the problem. I'll go so far as to say that it will probably run fine without a fuel pump also. Give me a few days to make the part(s) and do more testing.[;)]



speedster 1919 -> RE: My 2300 only likes one prop (2/16/2006 4:08:22 AM)

Not24 I don't think anybody mentioned this , but I noticed you posted an 1800 RPM idle once. I think Bax will support this also. Your idle needs to be about 2300 RPM with a low needle set for that speed. The loading should disapear. The F plug you pull out . Is it carbon black with some deposits? That would indicate too hot burning your oil too. Should be kinda wet and clean looking. You won't notice the 50 RPM loss with #8



speedster 1919 -> RE: My 2300 only likes one prop (2/16/2006 4:16:23 AM)

Not24 The 61 ST spraybar is fatter and would choke down airflow a little. I seem to remember some early ST3000 had the sleve in the carb barrel your talking about. Just rolled aluminum with a split and holes for the spray bar.



Not24 -> RE: My 2300 only likes one prop (2/16/2006 4:26:00 AM)

quote:

ORIGINAL: speedster 1919

Not24 I don't think anybody mentioned this , but I noticed you posted an 1800 RPM idle once. I think Bax will support this also. Your idle needs to be about 2300 RPM with a low needle set for that speed. The loading should disapear. The F plug you pull out . Is it carbon black with some deposits? That would indicate too hot burning your oil too. Should be kinda wet and clean looking. You won't notice the 50 RPM loss with #8


If you go back through this thread, you will read how I adjusted the LS needle. There is a very fine range for the low speed between too rich and too lean, and this setting works for 2500 and 1800. I would not set the idle for 1800 and expect it to pick up cleanly, but at 2500 it does. My point about the 1800 is that it would run there for 5 minutes and you could get it to pick up if you played with the throttle. At 2500, this is not an issue. The low needle works fine, it's the high needle that I find suspect.



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