captain2

My Feedback: (2)

if your clunk doesn't move freely from its normal back & bottom of tank location when flying upright - would it not then starve for fuel when nose down?. This is somewhat the problem I have with all my gassers [not just the Saito] but in more aerobatic conditions - sustained inverted, slow rolls etc. Have no idea what to tell you about the idle it sure shouldn't need 4k. Mine idles comfortably at something just a tick over 2k, my engine surging and quitting a high speed condition and this is what I think is fuel supply related. I'm now told that there is a clear flexible gas tubing available at any small engine shop - will let you know what I find.

fred45ty

Yes, captain2 except that I don't see air coming through the line when Ido this nose-down maneuver in my workshop. It just slows down rapidly and quits, without being due to air in the line. Now I did think that maybe it was experiencing an altered fuel flow rate because of the clunk getting into air in the tank and that maybe that itself is enough to cause the problem possibly actually getting too much fuel because of that. So yesterday I put a more flexible clunk line on. It made no difference.

Also yesterday, Ire-peaked the high and low speed needles ignoring the nose-down quit issue and flew the plane.

First flight, the top motor speed turned out to be woefully low and Ibarely could keep flying and land. Ithen re-peaked it again and it sounded good on the bench. Second flight the engine quit just after I left the ground and the plane crashed.

At this point, I think I've tried everything I know so I'm going to ask Saito to fix it.

captain2

My Feedback: (2)

'asking Saito to fix it'
and they likely will - my guess is that you have a replacement carb in your future - working great for me. Keep us posted - sent my engine in and had it back repared in a bit over a week. Really good service....

MercerAUST

I finally put 'old reliable' into the ground. This is a Hangar 9 Pulse 60 with a Saito FG-14 (the original version). The engine and ignition was stock with over 100 hours on it.

I'm not exactly sure why it went in, I was cruising at about three quarters throttle and practising precise manouveres, no excess speed or engine loads. After the crash, the tail and elevator were intact and working perfectly, the Rx was still connected with a steady light and no indication of a brown out, the aerolins worked and the plane seemed to check out fine.

I'm pretty sure the crash was not caused by myself - it appears from the last few momentsof flights that the flight surfaces locked. I think it wasperhaps the transmitter.

Luckily the engine seems OK except for the ignition system which is torn to bits. I'll replace it with a RCEXL ignition. The high speed needle assembly is bent, but I'll try it rather than paying Saito's exhorbitant prices. I understand that they use RCEXL ignitions now (rebranded for Saito), but charge about twice the standard RCEXL price for a replacement.

I like the Pulse so much, I'll pick up another one from the LHS.

captain2

My Feedback: (2)

my fg-14 was on a GP UCanDo 46. finally have given up on the FG14. Saito was nice and repaired it [new carb] the last time it wouldn't run, and it ran relatively well [9k, 14x6] when I first got it back. Didn't take long though and what I think are carb design issues resurface and then it won't run well anymore - so I went back to the FA82 in the same plane. Too bad too, the gasser really does well on this particular plane, if it is running right.

your bent needle is probably going to need a new carb body - the needle assembly is not available by itself and not meant to be user serviced. IMO, the needles/spray bar assembly are the root of the problems. Glad you got 100 hours out of yours though, I couldn't keep mine running right for more than a few hours between carburetor replacements. My FG-14 is now for sale - if anybody out there thinks they can do better with it - let me know, we'll work something out.

MercerAUST

Yeah, I know I can't just replace the needle. Saito only sells a replacement kit for the entire carb unit. I don't want to go down this route so I'm hoping it will still work.

captain2

My Feedback: (2)

doubt seriously that you'll be able to straighten out your HS needle. There is a critical fit at the spray bar and actually both needles that I would bet you'll not be able to duplicate bending anything back. This is the reason, I suppose, why you have to buy the entire 'carb body left' assembly and/or the complete carburetor, and possibly why the carb is so hard to live with and touchy to adjust - a fuel/air mixture quite different than what happens in glow engines.

I had similar needle damage on a dead stick [happened much too frequently on the FG14] and only was succesful getting it running again after I bought the $60 carb body. Then that got clogged up and I tried the $100 complete carb and it ran fine again for guess what - maybe 8 or 10 flights. So the last and latest round, send it back to Saito, they are nice enough to put yet another carb on it on their dime this time. 10 more flights [or so] now it sits on my workbench, homeless, of course.

Arruda

Captain2: I have had several dead sticks until I read in one of these threads, that the low speed needle of the FG14 and FG20 must be very rich. Once I did that, no more flame outs.

captain2

My Feedback: (2)

wish it was that simple. the low speed needle is set at the factory at flush to the throttle arm and works fine there for engine starting and idle - which should be about 2100 rpm. Starting and idling never much of a problem, coughing and sputtering at high speed and transition a different story after the engine is used a short while.
When any of the multiple carbs I put in were new the high speed end worked best at about 1 1/3 turns out to give me approx 9000 rpm on a 14x6 MAS. The high speed side of things is where the adjustment can be very touchy, but as I ran more fuel thru it the high speed needle had to be opened more and more [3+ turns out or more] to get that 9k, and the HS needle adjustment becomes unresponsive - a problem I contend consistent with the spray bar getting clogged and the engine not getting enough fuel. Engine transition also becomes terrible, as the needle is opened that much. When the carb is working right there is only a click or two latitude [somewhere between 1.3 and 1.5 turns out] where the engine runs right.
Maybe I'm the only guy out there that has been experiencing this, but I can not invest any more airplanes into something that has a 50-50 chance of deadsticking - not all my deadsticks are uneventful! All this said, I have actually been impressed with Saito's commitment to this engine and the service they gave me - but do believe that the carburetor [ or carb design] has some inherent problems that have'nt been solved yet

et76

Folks, got a dumb question.

Received my fg-14 on thursday. Is my first gasser.
Built a test rig yesterday and fired the motor today (start by hand).
I let it run at 3500 for approx. 20 min - all went well - lots of black oil dropping from the vent - guess this is a good thing showing plenty of lube for the crank...

But: How do you ajust idle rpm? When I start closing the throttle (main valve at 4 turns open - as instructed for wet breaking in), the motor slows down at approx 2200 and stops before throttle is completely shut.

Does the throttle has to be completely closed and idle screw adjusted to have the motor at idle?
Or do you trimm the tx to keep throttle a little open for stable idle?

Sorry for the noob question but this is my first gasser at all.
Had only one nitro engine about 15 years ago..

Thanks.

Tobias

w8ye

My Feedback: (16)

Sounds normal to me?

2200 is about as slow as one will idle especially when new

MercerAUST

Hi Captain 2. It might be worthwhile adjusting the Hall Sensor a couple of mm (in either direction) and testing at WOT. My ignition timing was a little out, resulting in an uneven and unreliable WOT. Since adjustment, it has been fine. Cleaning carbs and replacing spark plugs seemed to cure it for a little, but only temporarily.

captain2

My Feedback: (2)

although I am not running my FG-14 right now - you have 2 needles to adjust - the main needle opposite the throttle arm and the low speed idle needle which is the small brass screw in the middle of the throtlle arm. The initial low speed should be with that screw flush to the throttle arm. and the high speed needle at something like 2 - 2.5 turns out. At these settings the engine should start quite rich. At full throttle then close the high speed for peak rpm - the FG14 has a rather unique sound, it may help to do this with a tach. After peak rpm [maybe 9000rpm with a 14x6]is reached then richen the high speed needle at something about 200 rpm less then peak. Then test your transition from low to high and if the engine loads up or dies then the low speed can be adjusted as needed. My experience has been that this particular engine is very sensitive to relatively small chang in needle settings. My best results were with the low needle flush as recommended in the manual, with the high needle about 1.5 turns out. Hope this helps

MercerAUST

I finally got my new Pulse 60 with FG-14 back in the air. Despite the bent high end screw collar fixed to the carby housing, and which needs a pair of plyers to now turn, the engine seems to run OK in idle and transition. However, my effective reliable peak seems about 1000 RPM lower than my previous effective peak. My prop might be one size too large, I'm not quite there with the tuning, or I really need to replace the carb. I guess I'll need some more test flights. It was windy, with a few 2-stroke screamers racing around, during my initial maiden and I couldn't really hear what the engine was doing in the air!

Ernie Misner

yukonpete, how did the intake manifold get a burnt blue color in your cub photo?

Thanks, Ernie

sharps

I have been following this thread for a while. I put a 14B in a Funtana 50 last spring and have had some similar problems. I want to point out that my manual does reference having the low speed set flush but then underneath this is a table that says to set the needle initially 5 turns in from flush. I made the initial mistake of turning the low speed screw before I thought what I was doing when installing the engine and didn't notice the table in the manual that says to set it 5 turns in from flush. The initial setting for the high speed is 1 turn and 20 min. out. in this same manual. When I first ran the engine all seemed fine on the ground and during beak in and then I flew it and any sharp increase in altitude would result in the engine threatening to to quit and I would have to cut the throttle to avoid a dead stick. I struggled with this off and on and then was going over the plane a week ago and still feeling frustrated with this motor when I went through the manual and caught the real low speed setting. I replaced the spark plug and reset both needles and started retuning. It will run perfectly on the bench and it seems a sharp increase in altitude will cause a flame out if the high speed needle is set too lean which is at what the manual says is 2 clicks from the highest rpm. Mine has responded to an additional 2 clicks and doesn't flame out unless I pull a 3D maneuver to go into a hover. The abrupt vertical causes a flame out. I am still leaning out the low speed and as I do as long as I keep the high speed on the rich side the engine is improving. It appears with mine at least that the high speed needs to be set richer than Saito recommends and if the low speed is not set in from flush the 5 turns the engine will run on the bench and run rough at full throttle in the air if the high speed is richer than Saito recommends. Mine is smoothing out as I lean out the low speed and if it threatens to quit in the air I land and open the high speed one click at a time and until it doesn't quit. After I enjoy a few flights I then put it on the bench and lean the low speed and do it all again with the objective of getting it to run smoothly at full throttle in the air and not quit. I hope this sheds some light on this. I have probably 40 to 50 flights on this engine now. I don't give up easily but was getting close until I looked at my manual again.


Put two sets of wheels on so you can land upside down.

captain2

My Feedback: (2)

As you may have gathered, I have given up. Your descriptions of all the special handling and adjustments you have to do strike me as well considered and entirely conceivable. Still believe though that the root of our problems is in fact the carburetor itself. If you take a close look at those miniscule needle/spray bar openings you have to wonder how the engine gets any fuel at all, never mind how fuel flow is regulated. I literally got to a point that the only way I could get the engine to run reliably was to either replace the carb body or the entire carburetor. Too bad too, really like the way the engine runs when it is right. 9k or so with a 14x6 on my UCD .46 and even after downsizing the fuel tank to 6 oz it would stay up in the air 20+ minutes with normal throttle modulation. Plan on putting mine back on a test stand and trying closing down the low speed as you suggest...
Also think that Saito is on the right track - offering their entire line in gas. Fuel consumption and operation cost differences are amazing. Wonder though had they been able to use a Walbro [or something close] whether the engine would behave better.

WindGap

My Feedback: (3)

Sharps, im having the same problems(going vertical or incline) tuning the engine and engine failing likewise, but its a fg-17. Instead of leaning out the LS needle, i've been richening it as per sug from Arruda above. Each time i richen it, i would retune the HS needle and it appears to improve. Not fully tuned yet.

Let me know if you make any progress.

MercerAUST

Mine is running fine now. It turns out the ignition was damaged in my crash and wasn't sparking correctly. I replaced it with a RExcel ignition from my LHS. I had to fiddle with the Hall sensor fitting a bit so I could move the sensor 28 degrees anticlockwise from the original sensor, and change over the metal spark plug cap from the Saito ignition. Anway, I got the top end back

sharps

I thought I would offer an update after being out today. I leaned out the LS about 1/8th and ran it up to full throttle on the bench which was in the low 7000 range. I then leaned out the HS until the revs went up dramatically to around 8500. I have had it over 9000 previously but any quick elevator would cause a flame out. I then put it in the air gently after a good warm up and flew sedately for a few minutes. I then challenged it with a reasonably steep vertical and heard it splutter. I then landed and open the HS 2 clicks. I took off again and tried full throttle. It ran reasonably smoother ( better than previously) . I flew for a few minutes increasingly trying to get it to quit with both steep verticals and dives. It flew fine. The high speed in the air is smoother than it has ever been and my confidence after 2 more flights without a hitch has grown. I have come to the conclusion that when I make an adjustment I need the engine to be well warmed up and I also need to give the plug time to clean itself and for the new adjustments to settle in. My current needle settings are HS around 1turn and 10 minutes, LS about 5.5 to 6 turns in from flush. The full throttle on the bench after landing is very close around 8700 with the idle around 2100. The longer I flew it the better it seemed to respond and the smoother it seemed to run. Vertical climb with the funtana is not fast but seems limitless, I know it isn't but it was great in my book. I also did several circuits inverted with out flame out or spluttering and only a slight increase in rpms, I think. I find this motor deceptively quiet at full throttle and hope it continues to run the way it did today. When I next return to the field with it I will warm it up for 2 or 3 minutes minimum and then take off gently with no sudden climbing to get some ground clearance before I put it to the test. I hope I have it now and perhaps someone else can benefit from my experiences. I might add I put a felt clunk in the tank and it is so good I am going to have to take the tank out and extend my fill clunk as the motor wants to run for an additional 10 minutes. This clunk I put in a week ago and when I would empty the tank before today the engine would run for about 3 to 4 min. before reving and then quiting as it ran out of fuel. Today it took for ever to run out and then there was only a slight increase in rpms before it quit, I don't think I did anything differently defueling today, but who knows.

Put two sets of wheels on so you can land upside down.

MercerAUST

Glad it looks like you got your problems sorted. Yes, I've always found it best for a gradual increase in throttle on take off, a gentle climb out (I just use rudder to get into the circuit) and then a slightly downstraight run for a few hundred metres at WOT to fully clear the throttle at max prop revs. The engine then seems fine at any manouveres. If I'm abrubt on the initial throttle movements, or get straight into manouveres, it can sometimes deadstick.

I think you are right that the engine needs to be warmed up and that you must tune it in the air (eg make the adjustment on the ground and then get it back into the air to check the response). It is laborious, but you eventually get there. Tuning on the ground can be frustrating because the engine response (particularly with the LS needle) can be misleading and tell you nothing about the engine's response in the air under real flight manouveres.

Like you, I use a felt clunk which has the advantage of not needing to be fully immersed to suck up every last drop of petrol. I had to change to a 100ml fuel tank because it used to take forever to fully run the last of the fuel out on a 200ml tank. Even then, it still takes 3 or 4 minutes of running to empty the clunk and fuel lines etc. I'm too impatient for that sort of thing and normally just run it to empty in the air. You can normally (if no one else is flying) hear the surge as it gets close to empty and then haveone or two minutes to get it down before the engine quits.

sharps

Yet another day. I took the Funtana with the Saito 14B to the field today and let it warm up on the bench for 3 to 4 min. It was still uneven at full throttle but I took it off gently. I resisted the urge to lean out the high speed even though if seemed to need it and sounded like it was running far too rich. After about a 10 minute flight the engine was running as it had the previous day which is darn good. It appears to have taken 10 min. or more for the engine to warm up fully and start running properly. I had a couple of more flights and tried to get it to stall but it just ran great. This seems a very long warm up period but if that is what it takes I can live with it. the temp was around 12 degrees Cent. or 54 degrees Farenheit. The previous flights and tuning had taken place with the temp over 20 Centigrade or 70 Farenheit. I checked the idle and high speed on the bench before I put everything away and it was close to 2000 for the idle and 8500 for full throttle with no hesitation or loading up. I don't know if this will continue but will keep posting with results. I think I can still lean out the low speed just a tad but don't want to upset the apple cart for now. By the way I use an automotive paper filter on my fueling set up. I think having clean fuel is paramount.

Put two sets of wheels on so you can land upside down.

et76

Sharps, thanks for this really good report from the flying field beyond theoretics.

My FG-14 is working great on the test bench - so good that I decided to build up a SIG Sun Dancer with this engine.

As I work in the automotive development on engines I would like to share some of my thoughts with you concerning the points you figured out on that engine.

First of all is the difference between ground set up and flight set up.
As far as I know, gas engines with carbs are sensible to ambient air pressure changes. So if the motor is right leaned out on the ground, the additional air pressure by flying velocity may "lean it out" too much in the air.
Means: if the head wind of the flying plane is pressing into the cowl, it is increasing the carbs ambient pressure. That would affect the gas supply from the tank, which is not in the higher ambient pressure region: the fuel would be pressed back to the tank a little bit, after all the engine is getting leaner.
If this is right, you will have to get a quite rich setting on the ground to have a well balanced engine in the air. As SHARPS says.
Or as a alternative: get the whole carb (not only the intake) into the fuselage where it is not affected to head wind pressure and where tank and carb have the same ambient.

When we tuned our motorbikes with carbs using RAM air or eventurbos, we had to richen up the high speed needles to compensate the new intake air pressure.

So what do you think on this thoughts?
Did you ever think about getting the carb into the fuselage?
Did you ever think about using a servo for valve setting in the air?

Second one is the long warm up time.

I am not sure, if a little engine like this needs a warm up of 10 minutes and more.
Maybe there is another issue within the membrane pump in the carb.
As far as I have seen, there is a plastic membrane used as a flexible element in the SAITOs carbs.
Instructions tell to empty the carb after each flight day. I do not like this and asked SAITO if this is really necessary. They said yes, as there are materials within the carb which may corrode when exposed too long to fuel.
Maybe they think about aluminium contacting gasolines alcohol ingredients.
So by hook or crook, when letting the carb run dry, this means letting the plastic membrane go dry.
If this membrane is made of a material similar to tygon, there may be a problem with hardening when getting dry after gas contact.
Try it out: a new tygon tube is quite flexible. Get gas in it - it will stay flexible. But let it be dry for some hours without gas - it will become hard as wood.
The crucial point is: if you are getting fuel back into the hard tube, it will become flexible again after some time - at least half an hour or more.

So when you go back to fly next day, you will start with a hard membrane having less pumping power than a flexible one. After some minutes of soaking the hardened membrane, it will become flexible again and the carb pump works well.
Maybe this is an aspect of a quarter of an hour warm up time? Soaking time? :-)

SHARPS: did you let your engine run dry after every flying day?
Did you feel the warm up - time as if the motor is having not enough fuel (pressure)?

Just my two pence...

My sun dancer has the fg-14 already built in. I am currently working on tail feathers and then balancing. Hope to deliver you some practical input soon. Except turbo charging. :-)

Bye

Tobias

sharps

Tobias
I hadn't thought about what causes the lean out in the air compared with the bench. What you say makes sense. I think it would be a very complex matter to get the carb into the fuse but possibly a hose? Interesting idea and food for thought. A note on the warm up time: I found a faulty battery connection that was loose and with enough vibration would improve contact. I replaced this connection which has reduced the warm up time considerably. It still runs with a rich burble for the first few minutes and then smooths out. I may still have the low speed a touch on the rich side or you may be correct about the diaphragm as I do empty the carb after every flight. I am exceedingly happy with my last few flights at the field but unfortunately my field is now closed to driving in until probably March or April which means walking in. I don't go nearly as often at this time of year because of this. It's a lot of work to get everything in to the field so when I do go I take something smaller.
I like your idea about a servo to control the air intake and suggest another option would be to hook one up to the high speed needle, novel idea anyway and worth thinking about. Good stuff Tobias. I hope you will post the results of your first flights. On another note I can't believe how quiet this engine is and it doesn't sound nearly powerful enough to power my Funtana 50 vertically, but it does. I am not skilled enough to hover but it would in the right hands.

Put two sets of wheels on so you can land upside down.
Sharps

MercerAUST

I have a FG-14 that I always run dry and a FG-20 that I never run dry (different fuel set ups). I probably fly the planes about every three weeks on average. I must say I can't really tell any difference in starting or running. Both seem to run/transition well with a minimum warm up (perhaps a minute or so to taxi to the strip for take-off), but they can hesitate with abrubt throttle movementsor manouveres.  It might take three or four minutes at WOT in the air before I any hesitation is gone. If I do have unexpected problems, it is almost always because I have accidently knocked my high end needle extension and changed the mixture a few notches.