Well, we took my ultra stick 60 out this Sunday. About 2/3 thru the flight time, she quite. We thought, ok, dead stick. But after landing her, we noticed the spinner nut, and prop were not on the plane. Weard?! I had it good and tight, so I thought anyway. Is this just a freek thing, or should I have been using a little blue lock tight on the spinner nut?

You were most likely too lean, and it backfired and spit the prop off. Saitos are notorious for that when they are breaking in. a friend has 2 .91's, and he had a terrible time trying to get them broken in. Lost several props. Stay behind them on the ground!!

Ken, did you have double nuts on it?
Ed M.

Use a regular nut then a Spinner nut...

You did not hear it "pop" when it backfired..

Sloppy rich on a new Saito- But sweet motors when broken in-

My Texan with the Saito was pretty deadly when it was new

Yeah this happened to me today as well. I was breaking in my new .91 Saito and it was on it's second tank of fuel. It had about 20 minutes of run time on it. Near the end of the second tank I deided to open her up to see what kind of thrust it would pull. It was impressive for about 15 seconds, then "POP" it just quit. The spinner had come loose. The prop didn't throw, but both the nuts had come loose, and the blade would spin freely..

Just curious as to why this is happening, I have 7 Saitos including 2 twins and have NEVER had on backfire and loosen the prop. I break them in on a PSP Manufacturing engine stand sickeningly rich for about a hour before installing in a plane, but even on the stand have never had a prop come loose????

One of the problems with the commercial spinner nuts is the fact that the hole in them is too small to get anything into really get the spinner nut really tight enough to stay on. I got tired of that and now I make my own spinner nuts and I Make a hole in them so that a 1/4" shank phillips screw driver can be used to tighten them. This has solved my problem. See photo.

"NO" I do not recommend that loctite be used on a propellor shaft. Just my own personal opinion.

Good Luck

Lee

Wow, good input guys! No, I (we) did not hear any pop, or any thing weard. She was kinda high, so it may have. Just quite. I don't belive I'm running too lean, but will check again. As for break-in, I ran two, or three big tanks thru her. Way rich!!! Then have been keeping it rich at the field, or so I thought. I have about 8, or 10 flights on her now. So, do you think a dab of lock-tight will be "ok"????

Thx!!!!

If you set the engine so that it is "kind of rich" at the beginning of the tank of fuel, by the time the tank is getting near empty, the mixture will be approaching "kind of lean".

To be absolutely positive that the engine will never go lean during the entire flight due to normal fuel consumption, put one or two ounces of fuel in the tank before the first flight of the day. Then set the high speed needle valve with the model pointing straight up. If you set it "kind of rich" with just a little fuel in the tank, it will seem very rich when you lower the nose back down to level. Leave it that way and fly. You will be surprised at just how little time into the flight that the engine will run well. You will not be spitting any more props off of the engine if you follow this setting procedure.

Yes, the engine will sound raggy and down on power due to being richer than you are used to running it, but it is "safe" this way.

If you absolutely must have maximum power right from the start, buy an engine with a fuel pump or a pressure regulator built into the engine. Saito isn't one that offers this in much of their line up. Why? Because it isn't really necessary for the majority of flying styles.

Was it an APC or Master Airscrew. I had a problem with the MA on a Saito 91 on the weekend. Double nutted and never had a problem with APC. I was told that the grooves on the back don't seems to hold as well. So I CA the prop to the spinner plate. I only used MA becase a black prop looks better on the plane even though it is a little noisier.

It was an APC prop.

OK, I know I shouldn't be worried, but what's the problem here? I'm planning on breaking in my Saito 100 (soon!) and have a lock nut, but is that going to be enough? HELP!

Dont use loctite on the prop nut. You may never get the nuts off because once you loosen the nut a little, the shaft will spin in the prop when you are turning the nut.

Use 40 grit sandpaper disks between your spinner back plate and prop, and between the nut washer and prop. also on the Saito's the low end needle is quite rich. you will have to adjust it after break in to get smooth transition. Great tracters when adjusted properly.

Apparently it happens from getting the engine too lean before it is completely broken in. I had it happen on my 180 before I found out it takes a few gallons to get broken in properly. I started running very rich, and no more problems!

I did not lose my prop since I had a the second nut set up, but my prop got cut halfway through one blade (wooden prop) by the tru-turn spinner...while destroying the spinner (ouch).