Hi All,
To all of the satio experts out there here is a question for you.
I have a Satio 100 on a Funtana .90, but I'm having trouble with the motor.
It's hesitating in transition, will NOT keep a constant mixture and frustrating the
*&^$ out of me[>:]. I have taken it off of the Funtana and thought about sending it
in to see if there is more problems that are beyond a high and low end adjustment.
I am running a 17X4W, 30% Cool Power and have changed glow plug after glow plug.
Oh yea, I've been through about 5 O.S. F glow plugs since this whole thing started. Please
help!!!! Is there a trick or do I need to send it in? If I need to send it in where?

If the engine is mounted inverted it sounds like fuel is pooling into the head, I just read a trick to fix it if thats your issue, Forgot who came up with it but put a few washers between the engine mount and engine on one side only to angle it a few degrees so the fuel won't be dead center of the head cooling the plug at lower idle. when the plug cools it will give bad transition until it heats back up at higher RPM'S

Dauntae

I'm sure not a Saito expert but I own a few. And like us all I'm learning something everyday I stay in this hobby.
First thing I'd do is check my tank, fuel lines, clunk for a leak or a pinch. Is fuel fresh ? Prop balanced ?
Open the low end up a 1/4 turn or so more. Then adjust the hi end to peak then backoff rich about 4 clicks or 300RPM.
Mark your hi-speed needle position with tape, etc and run and/or fly the plane. See if your hi-end needle is moving. After a very little time of you adjusting the needle valve and the way these glow engines vibrate , it's no wonder the crummy little metal retainer clips fail. About half my engines do this. And the vibration it causes is directly linked with the torque of the engine and prop turning so you almost always have a loose needle that leans out. Rarely will it vibrate loose rich. (Maybe below the equator.
Sometimes have to fly the plane to get this to happen. Seems the vibration is less while the plane is on the ground.
To fix this problem. (If that's what it turns out to be.) I either get a second retainer clip and the added clips stops it. Or I use a small band of heat shrink .

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Why doesn't fuel pool in the engines that run well inverted?

Lose this theory. It is not valid.

The prop is too big causing overheating, and the crummy fuel is causing
overheating.

Dave is right. I didn't notice the prop size you posted. 15x6 APC is about the biggest prop a Fa-100 will spin correctly. At least mine liked the 15x6 anyway. Also try a gallon of 20/20 PowerMaster or other brand of YS mix. The Saitos love it at our elevation.

Thank you all for your input! The reason I posted this was because I have been
running this prop and set-up on cool power fuel (30%) for quite some time and
have been super happy with it. I think I have the grimmlens in my motor. But,
anyway all the tuning in the world would not make this thing stay lit. I had a more
expeirenced 4-stroke guy help me with it and after about an hour of tinkering, fusing and
cussing he looked at me and said send it in. Just thought I would post this for a brain-
buster! Oh by the way the motor is mounted at a -45 deg. angle, checked the valve distance,
fuel lines, clunk and glow plug(S) nothing seems to work. Does anyone know where to send it for
service? Any advice would be of great help!!!!!

Thanks Again
Chris

Sorry it's not a APC 17X4W it is a 16X4W if that makes any difference!
Thanks again for the input.

Yes,it makes a difference! I was amazed a couple posts back when you said you had been running that combo! A 17-4 is an good prop for a YS .91AC or 1.10AC but is a bit much for the Saito. The 45deg angle should be fine. For some reason many engines will run inverted and others just never will. Usually the problem appears when the glow plug is at the lowest point. In the Saito the plug angles in from the rear. I have never seen a 45 deg angle generate bad running . I would strongly suggest going to the next larger size fuel line. Replace ALL the lines, even inside the tank. Silicone lines can get micro-pin holes that you may never see but they will give you fits. Don't be too quick to send the engine off. Most of the time the problem is other than the engine.

BTW, Check the valves AGAIN. Please and do it carefully.

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You didn't say if the OS Type-F glowplugs burned out, or you just changed them to see if you could find an improvement.

If they are burning out, there are two things that can cause that. The first is setting the mixture too lean, OR, the engine is leaning out more due to vibration/fuel foaming. This will burn out glow plugs. OS Type-F plugs are usually good for a year or longer when flying a lot. If they are burning out, something is amiss.

Also, pieces of metal roaming around free in the engine will also terminate an OS Type-F (or any other brand) glow plug early. If you are sure that the engine is not going lean once airborne and if the glow plugs you mentioned have burned out, it is time to send it back to the service people. You just might save yourself a lot of money by doing so, instead of waiting for the catastrophic failure that is broadcasting its presence by burning out your glow plugs.

As someone else has stated, statistically, most "engine problems" are caused by fuel system irregularities. Still, sending it off for a quick check, AFTER ensuring that your fuel system is in great condition and is not foaming the fuel from vibration, is cheap insurance.

Chris,, I just sent off my Saito Fa.72 to Horizon. They will fix your problem . This one was heating up and acting poorly all of a sudden. I couldn't fix it so I sent it in.

I always remove the muffler, plug and lines. Then clean the engine good. (Makes the service guys happy.) Write a note about what it's doing and remember to add anything you want them to do while it's there. New throttle arm, needle , etc.
Don't forget to add your address , email addy and telephone number to your note.

Send to:
Horizon Hobby, Inc.
ATTN: Saito Services
4105 Fieldstone Road
Champaign, IL 61822

Depending on tank location or many other variables not all engines have the problem BUT if it does then this theary IS valid, If this does happen this will fix it but it does not mean all inverted engines have this problem nor did I say they do, I have many inverted engines without problems but have had it happen with a plane with a higher tank location. WOW some people just want to shoot down everything that is not happening to them.

Dauntae

No real big deal. You pretty much got it right. Some engines are known for not wanting to run inverted. Othere putter along just fine. Most of the problem engines do indeed have the plug right at the lowest point. maybe after a few years of honest open minded observation he will come to understand that which he told others to lose. Not likely,just maybe.

change the muffler.....or drill it out ...I have two 100 satio and they did the same thing.....change the muffler and they run great.....I think satio is having a problem with that cast muffler.......Terry

There is no problem with the cast mufflers, I have about 15 Saitos and have changed all the older ones to the cast mufflers, improvements all around.

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Sorry if I sounded rude. That was not my intent.

Four-strokes have the valves to let out lots of excess fuel. Two-strokes, as you know, aren't so fortunate.

I have seen various engines that were impervious to being ran inverted. Likewise, or conversely, I've seen engines that flat did not like being ran inverted. Fortunately, the bad runners were engines from long ago and all two-strokes.

I haven't seen any glow engine, lately, that is particularly sensitive to running inverted. I have seen YS engines that seem to be completely oblivious to whichever position they are ran in.

Personally, I do not run engines inverted as a rule. I'm getting old and lazier with every passing day, so anything that makes modeling more complicated than it absolutely needs to be is forsaken and relegated to the back burner.

Besides, I often pay more for an engine because it is pretty (like Hobbsy). The last thing that I want to do is to hide it away in a cowl. <G>


Ed Cregger

maybe I got two bad mufflers....but that was the problem....Terry Spalding

My saito keeps backfiring and throwing the prop off. Besides not starting. I have mine on a Hangar 9 Miss America, Inverted. Can anybody help me before I set it on fire.

Sure, I'll help. I'll send you my address, where you can send your Saito for proper disposal!

Seriously, your needle valves are way out of adjustment. Set them back to the original positions, according to the manual, and start tuning from there.