reyn3545

Count on it!

reyn3545

Good News! Well, at least for me. The FG-14's showed up today, and they DO have metal motor mounts!

reyn3545

Quick question on the Saito FG-14....

I got 2 of these earlier this week for a project, they seem to have a LOT of trouble firing. I did get one of them running yesterday for about a 20 minute break-in, but the other motor has never fired.

The hall sensors seem to be spaced a long way away from the hub magnets... is this normal? My other gas engines require a pretty tight tolerance to run properly. I would guess the gap on these motors is about 1/8 inch.

Pete Bergstrom

Most of the time the problem is getting fuel into and through the carb for the first time. If the close the carb completely and turn the engine over by hand you should see the fuel moving through the fuel line into the carb once you have some fuel there should be no issues with starting the engine. The spacing you refer to on your FG-14 sounds about right.

What's your test stand like? Is the fuel tank about in line with the carb or quite a bit below?

Pete

reyn3545

The fuel tanks sit just about level with the motors, the carb inlet is below the outlet on the fuel tank. No problems getting fuel into the carbs.

I was able to get the plugs to fire today, but had to spin the prop pretty fast. I was passing the magnet slowly over the hall sensor earlier, and it wasn't sparking. I spun it quickly (plug out, but grounded to the side of the motor) and it would spark.

I'm waiting on spinners and adapters to show up, they should be here later this week. Once they're installed, I can use the electric starter and keep the motor spinning consistently. I think that'll help.

This little plane I'm building should be a rocket ship once the motors get dialed in.... but it's going to land like a rock. It's a Beech Baron, about 78 inch wingspan, 15+ pounds.

yukonpete

My Feedback: (4)

In flight my engine is running a little off. It sounds like the fuel is starved for a fraction of a second every 2  seconds and you can hear it.

any ideas?

pirofreak

I am not sure if you are having same problem I had last week, but this is what happen to me. My FG 14 was running great for weeks then all of sudden it was sputtering badly in mid flight. I adjusted needle with no avail. It would sound great on the ground but as soon as airborn, it would sputter. Check the fuel tank and guess what. Fuel line has come off the brass pipe in the tank and engine was sucking air. I just was amazed I didn't get dead stick. I flew like this for about 10 flights without dead stick. I did put wire ties over the fuel line and it still came off. This time around I put some lead soldier on the brass tube prior to putting wire ties on it. Hopeful it will stay on this time. That solved my problem with in-flight sputtering. I don't if this is what is happening to yours, but it may be worthwhile checking your fuel tank.

reyn3545

Here's a pair of FG-14b's running in a Baron that I'm building....

http://www.youtube.com/watch?v=XbbgMp7IWkk

I've still got some tuning to do. The right engine won't idle well once it's tuned in for good high speed. I think I need to open up the low speed valve a little.

w8ye

My Feedback: (16)

One engine is not running well at all.

reyn3545

yep.. the right side is giving me some headaches... when it runs well at full speed, it doesn't idle worth a darn. It's kind of set in the middle right now, which will keep it running, but not great. I'll spend some time on that in the coming week. It seemed like it ran pretty well before I put the nacells on, although I can't imagine that alone having this much of an impact.

reyn3545

After an hour or so of fiddling around with the motors.. the right motor is purring like a kitten, transitions are great. I tried to smooth out the idle on the left motor a little, and now it's worse than when I started. When the transition and top end is good, the idle will start out well, then get rough and die. Opening or closing the low speed seemed to have mixed results, very inconsistent. At one point, I would think it's starving, the next thing I would think it was flooding. I've tuned a ton of gas engines, but this one is kicking my butt! I'll get it eventually.

I started with the low end about 4 1/2 turns out (by the book) on both motors, and on the good running motor, it's about 6 turns out right now. The high speed needle is about 1 1/2, where it should be.

w8ye

My Feedback: (16)

The needles are very sensitive

reyn3545

If I was smart, I'd pull the motors back off and tune them on the test stand, but these things are almost impossible to get apart. First you have to remove the muffler, then the bottom nacell cover, then the motor, then the nacell, then the tank, then the mount. ARRRGH.

Or, I could just twist on the needles for a few more weeks. Maybe I'll start taking it apart.

reyn3545

OK.. I decided to do the right thing and pull the motor off.

A couple of hours today of fiddling with high and low settings, I think we're finally there.

With a 13x8 3-blade prop, it will idle around 2000 and jump up to 8900 with smooth transition. That's good enough for me. I would like the idle to be stable at lower RPM, but with the heavy plane I have, it won't make any difference.

These props are still too close to the grass, so I've ordered some 12x8x3 props. That should give me plenty of power and a little faster RPM also.


Now, as I finish the "testing", I realized that all of my testing was with the motor sitting upright... it actually sits inverted in the plane. I guess the only difference would be that when inverted, it's a downdraft carb. I might still need to do a little final tuning when I put it on the plane.

w8ye

My Feedback: (16)

Be careful about you tank height. The pump is not very strong and fuel will siphon through the pump becuae there is no regulator

Treat it like it was a glow engine as far as the tank height goes.

reyn3545

Yep... thanks!

reyn3545

Motors are tuned up and back in the plane... here's a few pictures.

reyn3545

OK... officially starting to pull my hair out over these motors...

One runs like a top. Smooth idle, good transition, steady 8900 RPM on the top end.

The other idles very smooth, transitions well, but the top end will hold for about 10 seconds, then start to slow down and speeed up, eventually dying if I don't go back to idle. It acts like it has a fuel supply problem, but I've checked the lines inside and outside the tank... all are tight, and I haven't been able to find any leaks in the line. The fuel like going to the motor doesn't have any bubbles in it, so all looks good.

Any ideas as to why it would be surging like that then dying? Both motors are about 1 1/4 turns out on the high needle, but I've gone as many as 3 turns out on this motor with no improvement.

I want to get this plane in the air BAD... but if I can't get the motors more dependable, it's just going to be a hangar queen.

w8ye

My Feedback: (16)

One guy contends that there is oil behind the diaphragm and that the nose of the plane must be held vertical while the engine is running to get the oil out the vent hole? Sounds like a long shot to me?

reyn3545

Sounds like it to me too... but it's worth a shot.

reyn3545

I give up... this engine is going back to Horizon next week.

I tried replacing all of the fuel lines, inside and outside of the tank, made sure everything was airtight. I also went from a 3-line tank setup to a 2-line. When I had a 3-line setup, I would have to open up the throttle and turn off the ignition, then crank on the motor with the starter for a while to get gas into the carb. With a 2-line setup, I just blocked off the "fill" line completely and put a "T" in the line from the carb to the tank. that "T" became my new fill line... the thinking was that some fuel, with pressure from the filler pump, would make it into the carb for easier starting... that plan worked like a charm.

I let the motor warm up at low speeds for a minute or so, then went slowly to full throttle... still surging. No amount of twisting on the high speed needle would fix it. I don't know if it's the motor or the ignition.. but both are going back to Horizon on Monday.

The other motor runs SO smooth.. I tached it today... on a 12x8x3 prop, it's idling about 1800 RPM and the high end is about 9200.... much better than with the 13x8x3. I'm sure these motors will get the plane up and down, but I'm not going to go down the runway until I have 2 dependable motors.

MercerAUST

I'm sure you've checked the server linkages and there is no twitching, that the fuel vent line does not inadvertantly exit into a low pressure back-draft, that the throttle barrel has a smooth transition with the throttle linkages, and that the spark plug is clean (or even closed a fraction more than recommended), and have tried on its own ignition 6V battery.

I had some twitching from electrical interference causing surging, and fixed with a Sullivan pushrod. I had a problem with the engine running well on idle/WOT/transition, but being unreliable on constant high throttle (fixed by replacing my fuel tubing with narrower gauge, getting rid of any unnecessary lengths of tubing, and relocating some of my tubing to avoid any being higher than the carb. I've still got popping at WOT, but will try regapping the sparkplug and more tuning.

I hope to get in the air next weekend. My grateful thanks to Pete Bergstrom for his help and advice.

jimmyjames213

My Feedback: (2)

maybe your prop is a little to big and its overheating????? a 13x8 is a lot of prop for a .82 glow (more like a .91 prop) and yours is a 3 blade making it even worse.
ill let the gas engine guys recommend a prop but maybe a 12x6 3 blade would be a lot better???, at least try the 12x8x3 on the other engine

reyn3545

Thanks for the suggestions. Yep, tried them all. The recommended 2-blade prop is a 14x6, so a 12x6 3-blade should be fine. The other engine is running this same prop without a problem.... and it's a Master Airscrew, so it's a good bit lighter and a little more flexible than an APC would be.

Steven Chen

Spitfire with Saito FG 14
[youtube]http://www.youtube.com/watch?v=f5_I8QvGbFc[/youtube]