RandyBond

My Feedback: (1)

I've recently purchased a Saito FA 100 motor from a friend. It's just barely broken in and I've got a couple of questions.

1) He had the motor mounted in a Hangar 9 P-51 Mustang (ARF). It flew great and the engine performed well. The motor just seemed to shake the living daylights out of the airframe. He used the motor mount that came with the kit and it wasn't an isolation mount on the P-51. I'm contemplating putting the Saito 100 in my Top Flite P-47, but I'd like to not shake the plane apart if possible. Can someone recommend a decent isolation mount for me? I know four strokes are going to have more torque and more vibration. Am I thinking correctly that using the proper isolation mount will minimize the vibration transferred to the airframe?

2) What kind of fuel do the four strokes like? I'm more interested in longevity that all-out performance on each flight.

This is my first FS.... so go easy on me.

Randy

Flyboy Dave

My Feedback: (21)

Randy....if he was using the metal engine mount that comes with the plane,
he got all the vibration he was asking for....usually those mounts break in a
short period of time from vibration.

You'll get a difference on this....but the Saito will run "better" on 20/20
YS/Saito Powermaster fuel, and an OS "F" type plug than it will on any
other combination.....I have seen this for myself.

FBD.

w8ye

My Feedback: (16)

The 100 also vibrates more if the mixtures are not set correctly.

I've been having good luck with the Great Planes 60-120 plastic mount.

Enjoy,

Jim

old bird

Randy, I am running the same engine in a Hanger 9 Corsair. It is mounted at the recommended 7:30 position, semi-inverted. We had to lower the fuel tank .5" to get a good idle. I am assuming that you are running your engine inverted. You should have plenty of room in a P-47 to put the fuel tank where you want it, with the center line of the tank lined up with the needle in your carburater. This made a LOT of differance in our Corsair, the engine went from a bone shaking idle and low end to a nice smooth tick over. The high end of both of our Saito engines is nice and smooth. Both of our Saito engines came with the idle screw turned out about 4 turns too far. If you GENTLY turn your idle screw all the way in, and the back it out about 2 full turns, you will be in the ball park. If your fuel tank is too high, this will prevent you from getting a good setting on the idle. Our Saito 100 shook like crazy on the test stand at low RPM's when we were breaking it in, the idle screw and tank position is the key to making these engines do their best, IMHO.

Hope this helps, best from old bird.

udi maman

My Feedback: (18)

ןi have it also on h9 p 51 arf
you need to tune the saito 100 corectly if not hi is a big shaker.
and balannce your prop i use master k ser 14/8
udi maman
israel

Richard L.

My Feedback: (24)

It is best to set the low end on a Saito while the engine is idling. Use a small flat screwdriver and slowly turn the idle screw clockwise to lean out the low end while listening for a rise in engine rpm. Immediately stop leaning out the low end when the rpm stops increasing and richen up around 1/16-1/8 turn. Trim the radio to bring the idle back down. Let the engine idle for 30 seconds. If the engine slowly bogs down and dies, the low end is still slightly too rich. On the other hand, if the throttle stick is quickly pushed forward and the engine dies, then the low end is slightly too lean. Adjust if needed.

Cyclic Hardover

My Feedback: (3)

When I built my little P-51. I put a very tiny hole in the cowl just for this purpose. I can adjust it without removing the whole thing


[quote]ORIGINAL: Richard L.

It is best to set the low end on a Saito while the engine is idling.

bako

shaking can cause preignition. if using high nitro and hot plug, it will shake more

William Robison

My Feedback: (3)

Not so,sir. Detonation andpre ignition can cause shaking, but not the other way around.

All the Saito engines up to the FA-100 are smooth when adjusted correctly. The FA-120 and larger do benefit from resilient mountings, but with the 120 and somewhat less the 150 they aren't necessary. I think the FA-180 should always have a soft mount.

Bill.

Richard L.

My Feedback: (24)

Not true. No way can shaking cause preignition.

Again, not true. Using high nitro and hot plug will slightly smooth out the idle. People having been using 30% nitro and Type F plug with good results.

Heritage rider

My Feedback: (2)

I have a different question about the Saito 100. I had a similar situation with a newer FA 82. It is better now.

I have 4-5 gallons fuel so I think it is fully broken in. Just adjusted the valves for the first time. It always starts easily and runs strong. In a UCD 60 with a 15x4 APC I never want for power. I broke it in by the book.

I was getting short fly times on a 16 oz tank (7 minutes). Rarely use full throttle. I just adjusted the idle needle as described in an earlier post. It ended up about 1 3/4 - 1 7/8 turns out. Also readjusted needle valve. Peaked at 9300 and I backed off to about 9100. I was getting a lot of smoke from the engine but I assume this was fron the rich setting of the idle adjustment.

After adjustment, I timed a full throttle run. I got about 9 1/2 minutes. I assume I can now get 10 minute flight times fairly easily. I seemed to still be getting smoke but not as much. I was running Powermaster 20/20 and currently running Omega 15%. OS F glow plug. Can't tell any difference in flying but have never used the tach to compare.

The question: How do the times and the other numbers sound to you? Interestingly, a friend of mine was flying the other day and lost his throttle control after a few minutes in the air. Full throttle so we thought that it would not take too long to run out. He flew about 10 minutes and gave me the control cause he can't look up etc. that long. I flew another 25 minutes!! It is a APS (I think) 120 four stroke with 20 oz tank. He has it rich. My 9 1/2 minutes don't make since compared to his about 30 minutes. Of course, he may have been slightly less than full throttle but I have heard his engine many times and it sounded like full throttle.

Do you think I am right about the smoke coming from the rich idle adjustment? I was worried a little about bad ring, scorched piston etc but can't see how I would get 9300 rpm out of the resulting low compression.

Is there really much difference in the two fuels other than 5% nitro?

Thanks for any help with this. I would particularly be interested in RPM with same prop you observe as well as full throttle run times. BTW, I love these Saito engines.

Jim

William Robison

My Feedback: (3)

Rider:

An easy rule of thumb, and it comes out pretty close, for fuel consumption on a Saito at full throttle is one ounce per minute per cubic inch. This is with the carb adjusted correctly for best operation. In other words, the 150 should burn 1.5 oz/min, the 100 then will take 1.0 ounce per minute, and so forth.

Your time of 9 1/2 minutes with a 100 on 16 ounces says you're still quite rich. Or you are losing fuel somewhere.

The Omega has castor oil in the blend, it will give you just a little more smoke than an all synthetic fuel. I prefer the Omega, I use it in mine, all at 15% nitro.

And yes, you should have at least a slight smoke trail.

Bill.

Harry Lagman

I also have the FA-100 in an H9 P51 and I am using the supplied mount. Its vibration level is about normal for this sized four-stroke. I am satisfied with this engine's overall performance and short break-in time. After the requisite 10 minutes of low rpm running, I set the main needle a little rich, then the low end (leaned it down about 4 turns!) and flew. It has run perfectly since.

One thing Saito seems to do is supply their engines with very rich low speed jetting. I notice that a lot of guys run with these way-too-rich factory settings, resulting in very rough running at anything less than full throttle.

The FA100 seems to be a bit of a guzzler though. Mine uses considerably more fuel than my OS .91 Surpass and deposits much more oily spooge on the model. My flight times are acceptable but I could never accuse my FA100 of being miserly on fuel!

Build-n-flyer-RCU

My Feedback: (4)

Not only will having too rich an idle setting cause vibration, it will also drastically increase fuel consumption (unless you fly at full throttle all the time). Set right, my Saito 100 gives me at least 15 minutes of flight time on a 16 oz tank flying IMAC-style patterns, which may not be great but its pretty reasonable.

But with the factory idle setting on the bench during break-in, a 16 oz tank won't last even 10 minutes. And this is with the top end set close to peak!

Walt

Cyclic Hardover

My Feedback: (3)

You got that right. One thing that I do in all my planes whcih i consider are for speed is my timers are set for 5 minutes and i 'm coming in.
This way I know I have enough for a few go arounds if necessary and to land without worrying

rg wilson

I wrote a couple of months ago about a factory rebuilt Saito 150 (crash damage) that I had sent back to Horizon several times because it would not start except after a long and hard struggle. I finally sent it back once again, after several months of effort and would you believe, Horizon sent me a brand new Saito 150 which starts right up and runs fine. I have it in a Funtana 90 and yes, it does shake a lot because it has a huge piston slamming around. Nothing much you can about that on a single.
Got to tell you that I have a huge amount of respect for Horizon Hobbies. They are first class.
Sometimes we forget to say "thanks" to the folks that do a good job.

Bob Wilson
NC Mountains

Richard L.

My Feedback: (24)

My Saito 150 doesn't shake very much. It took me a while to get it to idle inverted. However, after a couple of gallons, it developed a loud metallic clacking sound between idle and 1/4 throttle. The engine already has three deadsticks at half throttle. The prop shaft now has 1/16" of side-to-side play. My buddy's Saito 100 on his H9 Mustang is developing the same symptom, and we both have been using fuel with castor oil. I think our front bearings are going out.

William Robison

My Feedback: (3)

Richard:

No sir, they have already gone out.

Even mistreating the engine with 100% synthetic oil should not cause that much wear. You need to find out what you and your buddy are doing to cause it.

It is possible the original bearings were just trash from the maker, but that's a little hard to accept also.

If they are still in warranty (at least the FA-100 should be) let Horizon inspect and repair them.

Bill.

Richard L.

My Feedback: (24)

I will try to disassemble my 150 to see what happened. When I removed the valve covers, the left one (as viewed from the front) was full of oil, but the right one was fairly dry. We both use Powermaster 15% nitro with 18% synthetic/castor blend, and we both run our engines 300 rpm on the rich side below peak.

William Robison

My Feedback: (3)

Richard:

I know the 100 has to be fairly new, but how much time do you have on yours? Even a badly out of balance prop/spinner set shouldn't cause the bearing to develop radial play to that point. One or two thousandths, maybe, but never as much as a tenth of an inch. Just about has to be a bum-from-the-start bearing.

Bill.

Richard L.

My Feedback: (24)

Not much time on my 150. Only two gallons. I always balance all my prop religiously with Top Flite magnetic prop balancer, so it can't be the prop. I'm also using a Tru-Turn 1 1/4" prop hub and not a spinner, and that prop hub is also balanced. It must be a bad bearing from the start. I will ship it back to Horizon after I check things out. It's too bad because this is one of the few smooth running 150's out there.

hockeyrules99

My Feedback: (7)

quick question on the saito 100 ...just bought one about two months ago...ultra stick 60 ...is the plane is it on...broke it in per instructions ran 1 gallon through it on the bench stand...maidened the US60 two weeks ago...have about 6 flights on it...low speed still not adjusted to peak ..WAY rich on low end...would set high speed for around 8900 running 15nitro 20 oil ..swinging 15-6 prop. After sundays flying I was checking it over in the basement ...when you grab the ends of the prop you can feel play in shaft...I asked the LHS and he said it was normal to have play like that ...just wondering if thats the case or should I pull it out and send it back..or keep flying ..see if it gets worse?
any input would be helpful ..
thanks
John

hockeyrules99

My Feedback: (7)

oh and I do know for sure the prop is balanced...

William Robison

My Feedback: (3)

John:

If you can feel more than the very slightest amount of play in the crank, or even at the prop tips one bearing or the other is loose.

When the engine is cold you should feel no almost play in the shaft, one or two thousandths inch is acceptable though. Many bearings have that much clearance from new. If more ship it back to Horizon for new bearings.

Much better than stock bearings are available, and not too expensive. But until the engine is out of warranty, or at least has a lot of hours on it, you shouldn't have to pay for them.

Bill.

hockeyrules99

My Feedback: (7)

one or two thousands of an inch ...not sure how much it is ..but i can feel it for sure..and the engine is cold...@68 F or so in my basement...will the problem(if there is a problem) get worse in the next couple of flights...I know when bearings start to fail on equipment I work on ...when it stars it doesnt take long to go from mild to wild so to speak