Jesse Open

Dave,

7075 T6 has very high tensile strength, often rivaling mild steel. Has a good tin content which makes it a decent bearing material. Silicon is fairly low so it is not excessively abrasive. 7075 machines and finishes beautifully. Those bearing installation tools I have posted were machined from 7075.
At work we used 7075 extensively for dies to form stamped steel parts

Unlike boxer twins, one must keep reciprocating mass in check with single cylinder engines. Added mass also increases tensile loads around TDC reversals.

Kenki

I purchased a Saito FG 11 for a 55 size Cessna.
I have put 4 tanks of fuel through the engine, at recommended mixture, and following the break in procedure.
I am finding that I am not able to get the engine to idle unless the throttle is half open. I have tried adjusting the low end needle, but it does not seem to have any effect.
On the top end I was able to get the high speed to 8000.
The engine still runs rough, so it may need more time, but I am concerned about not being able to idle until half throttle, anything lower and it dies.
Any advice would be welcomed.

1200SportsterRider

Ken, welcome to the Saito Nuts Club, here is my FG 11 turning a Xoar 13 x 7 at 9,330 and Idling at 2,140, the fuel is 90 octane, ethanol free gasoline with 20 to 1 synthetic lube. I don't think you have high speed needle at full peak. My new gallon of fuel has Redlne lube. The FG's do like to run rich.

Hyjinx

I remember you lost much in that fire Pedro. I was fortunate to have gotten away with no one harmed. Was the nicest vehicle I ever owned. The insurance company has been fair so far. Sue found that van and she already found me a comparable one with a little less miles. Should come out as a wash hopefully.

Kenki

Thank you for your reply, I am running 20:1 Amsoil, but only octane 87 percent, and here in Cali, we have ethanol in our gas.
I am going to build a quick engine stand, and try to work out the issues.
Do you think the idle at half throttle has to do with the high end not being at peak?

1200SportsterRider

It's more likely the LS needle setting being too lean. It should be between 1.7 to 2.0 mm below thee flat surface of the throttle arm. 2mm is just over 1/16th inch. Personally, I would back the LS needle out almost flush with the throttle arm, then I'd go to full peak on the HS needle and then fine tune the LS needle.


About like this

Glowgeek

Hello, Kenki, welcome to the thread.

I agree with others here that if the engine just quits running below half throttle then the low speed needle (LSN) is too lean. Turn it out a half turn and try again. Run the high speed needle (HSN) at 250-300 rpm rich of peak to compensate for prop unloading in the air. Once you have attained a suitable idle rpm work on leaning the LSN as far as possible at idle, this will stop your engine from hanging at high idle in the air due to prop unloading.

Amzoil has great products, I use their air filters, engine oil, gear lube and tranny fluid in all my autos and lawn equipment EXCEPT in my 2 strokes and 4 stroke model engines. Their 2 stroke engine oil has a known history of leaving higher levels of carbon deposits than other high end synthetic 2 stroke oils. Red line oil, Stihl Ultra oil and Castrol 2T are better choices IMO. I run Stihl in all my 2 strokes at 40:1 and in 4 strokes at 15:1. Please note that changing oil type or mix ratio will require retuning. Saito FG engines run fine on ethanolated 87 octane gas.

Also, be aware that gas has a much narrower combustable range than methanol, so once rough tuning has been accomplished fine tuning the needles requires VERY small changes, especially for the LSN.

Kenki

Thank you very much for the information. I will give this a try and see what happens.

1200SportsterRider

Since I mentioned this before I'll dd a little, the Stinger 10 cc is mostly mounted, the throttle is a puzzle, any suggestions? The engine sure was packed well.


It fits well.

What to do, what to do.

Glowgeek

Yep, sometimes getting the throttle linkage figured out on gassers burns some brain cells.

Jesse Open

Sure seems that way

Jesse Open

From here it looks like a drilled clearance hole thru the mount would be a good start.

1200SportsterRider

That was Lonnie's suggestion on the phone as well, thanks, I might have to use a ball link to fill that big hole.

Jesse Open

If the ball link shank is too long perhaps a "z" bend (?)

Or should I have called on the phone

FlyerInOKC

My Feedback: (6)

Would one of these help?

https://www.dubro.com/collections/al...83506497&_ss=r

the Wasp

My Feedback: (1)

I agree, drill a hole right through the mount. the same size as the mounting holes. it's not going to be any weaker than the mounting holes. use a shortened nylon cleaves.
humm, for that matter, my 4-Star 120, with the Saito 120 setup for gas used a SS braded wire and the guy just used an EZ-Connector that clamped the wire. no cleaves.

Jim

1200SportsterRider

Here is a Saito 72 where I did that exact thing. Thankyou gents.


On of my Saito 72's on ?


On a Goldberg Tiger 120 for Saito 150-s

Jesse Open

Gee whiz, that's a whole lotta hardware!!!

Glowgeek

For ignition engines it's a good idea to introduce some form of plastic component into the throttle linkage when using a metal control rod or cable as it helps suppress ignition noise and engine vibes.

Most of my gassers use heavy weedeater line instead of metal cable and the plastic sleeve I use is aquarium air pump tubing.

1200SportsterRider

Like this, I gave this method a shot and said, hey this is a keeper.



The muffler bolts hold it precisely in place.

Jesse Open

Nice job there Dave. Should be in the air soon.
That ARF version is a lot different from the kit built.

Yes,
Breaking the metal to metal close to the engine is simply a "given"....goes without saying.But I was quite sure you knew that

I use Z bends at the throttle often. Always at the end of a Sullivan nylon pushrod.
Then again, 50Mhz PCM Futaba is pretty much interference bullet proof anyhow.

I like to stick with large, fast servos with fine resolution on the throttle as well.

1200SportsterRider

The throttle spring on the Walbro was really strong, in my effort to disconnect it, it sprung back to another catch and now has about 1/3 it's previous strength. The servo you see a JR propo E 397 has 34.7 oz. inches of torque at 7 volts. The throttle spring load does not faze it at all.

Glowgeek

I use old futaba 3003, 3004 and other slower less accurate servos than available these days. Those servos open and close the throttle faster than I do during flight anyway. The accuracy and centering is fine with those old servos too, because I don't run engines at their lowest capable idle rpm. When running Life batts I drop in a couple of diodes to buck voltage if necessary.

Jesse Open

Different "wants".
I want servos that are as close to instant as possible. Also like that absolute, super repeatable ifle setting.
The servos that lose the edge get moved out.

Glowgeek

I only have a few 3D planes where snappy acceleration is necessary, I mostly fly pattern and scale where that is totally unnecessary. Not even beneficial due to the requirement for smooth throttling.