William Robison

My Feedback: (3)

Mike:

Sorry, I gave only a partial answer to your question about coking the valves. Excess or rapid build-up can be caused by several things, too much castor oil is only one.

Synthetic oils burn at much lower temperatures than the castor oil, and some additives will also cause the coking. Buying commercial fuel this is not an issue, but if you are trying different oils in mixing your own fuel it could be.

Regardless of what oil you’re using, the deposits are an indication of running the exhaust valve at a high temperature. The remaining oil in the exhaust flowing around the valve will hit the hot stem and solidify. For most of the port and valve area there’s enough velocity of the gases to keep everything blown off, around the upper end of the stem there’s “Dead� air, ‘specially when the valve first closes, the solids will stick. As it builds up there is more disturbance of the air flow, this aggravates the rate of deposit.

The fastest build-up is when you have been running at a high power level, and then slam the throttle shut. The valve is still at its highest temperature and the air flow has suddenly dropped to a minimum, this allows the oil in the exhaust to stay on the stem longer, with less tendency to be blown out before burning. Full scale air cooled engines also are sensitive to this, as well as being warped by too rapid cooling.

In other words, it’s going to happen. You can decrease the rate by using only high grade oils, and yes, by good throttle management.

Removal? Recommended method is pulling the valve out of the cylinder and scraping it off, being careful not to scratch the stem or valve face. Not recommended is reaching into the port with a knife and scraping it while the valve is in place. It’s too easy to displace the valve while doing it, and dropping some of the material into the cylinder. Best just to leave it alone until the engine comes down for inspection or other repair.

JettP:

The first step in balancing a prop should be sanding all the casting flash off, but even after doing this the APC props are still much sharper than other brands. And as I said before, with so much power I don’t feel the added performance of the APC is worth the risk.

And on the black from the case vent – it’s perfectly normal to have some black as the engine is running in – the break-in process is having all the metal parts wearing to an ideal fit, there will always be some metal coming out until everything is seated. After that you’ll still have some metal from the usual wear, but not enough coming out to notice in normal running.

Bill.

rajul

My Feedback: (58)

Bill, thanks for the explanation on the valve stem fouling. Why is it that some engines have the vent at the front, and some at the rear of the crankcase? Isn't the front the best place as it allows oil to get into the more critical areas i.e. the valve gear train?

DandGMartin

Huck328
WOW, that's one sad mess! Hope the rest of your components (servos, rec, etc) survied it ok.

All:
Sure is a lot of posting has been going one in the last day or so. I noticed 13 viewers at one time last nite.

William
Regarding cylinders, I quickly looked on Horizon for a replacement for my FA80 and found nothing. Do you know if there is a different one that would interchange ? ie an 82 along with a new piston and ring and would it accept my other parts valves, rockers intake exhaust etc? Thanks

Don

w8ye

My Feedback: (16)

$72 plus $4 postage and its yours

http://www.horizonhobby.com/Products...rodID=SAI8001C

If you have a black engine, here is the jug for it.

http://www.horizonhobby.com/Products...dID=SAI80GK01C

William Robison

My Feedback: (3)

Mike:

The forward case vent location is better for just the reason you supposed – better cam lubrication. When Saito started using the plastic back plates they had to move the vent, the plastic wouldn’t hold the nipple securely. And the later designs are all front vent.

Don:

Jim gave you the part number, what he didn’t say is that the FA-72 uses the same cylinder, piston, and valves, it just has a shorter stroke.

If yours is the older ABC version the valve springs wont fit the AAC cylinder. Not a bad idea to replace the springs anyway – they get weaker with age.

Bill.

scratchonly

Clarence Lee recommends dribbling some fuel injector cleaner into the carb while the engine is running to clear carbon deposits. What do you think? Has anyone tried this?

P47 Jug - Al

My Feedback: (1)

Someone suggested trying a different prop for loading differences. I tried an APC 14x6 today and my noise is gone – at least on the ground. I tried a new Top Flight 14x8 and the noise is present. I made a mp3 of both props and although the sound is not a perfect recording, there is a noticeable difference and you can hear the objectionable noise I speak of.
[link]http://members.cox.net/p47-jug/PropNoise.htm[/link]
Although stated earlier, the engine has only a gallon through it and may be rich. The noise has always been present with the top flight prop. Unfortunately I do not have an APC 14x8 to try. Changing the high end between rich and lean does not change the noise and the noise is present from the mid range up. Is this a case for trying a different 14x8 prop getting away from Top Flight or is something else going on? The Top Flight is noticeably lighter too.

I hope the sound helps. As they say a picture is worth a thousand words, I hope a Saito mp3 helps with the diagnostics.

Thanks

afterburn

Dennis,

I have the new 2.2 on the great planes yak 54. I have 3 more saitos on different aircraft I like their power and sound. I can't get the motor to idle for a smooth transition to high end for flight testing. What is the correct low end and high end starting points? I have a 20X8 prop and running 18% morgan cool power. It seems like it is runnnig very rich. I did install large fuel lines because of the engine size, would this make a difference?//

any sugggestions?

thanks blaine

William Robison

My Feedback: (3)

Al:

“Methinks he doth protest too much.� I didn’t think your sound files would do any good beyond confirming detonation or preignition. But what I heard was just the different noise of two brands of propellors. Not to worry about. Put a MAS on and it will sound a lot like the TopFlite wood, a Zinger will be closer to the APC.

What I did hear to worry about was the uneven RPM at full throttle, as though there was a tendency to go lean. This most likely is just due to the remaining stiffness of the engine – not yet fully run in.

All in all, I’d say just enjoy the engine, ignore the noise when you’re running the TopFlite props.

Bill.

JettPilot

My Feedback: (6)

Huck,

I would sell the parts to WR and get a new engine, you will spend almost the price of a new engine fixing the old one and there is no guarantee it will work, or that you have not missed something elese that may be damaged. For a little more you get a brand new engine with a 3 year warranty...

WR

I was deeply disturbed at seeing someone destroy a Saito engine like this Dont people get kicked out club Saito for this type of thing ?

JettPilot

rajul

My Feedback: (58)

On the contrary, he is trying to save that engine. He deserves a lifetime membership

William Robison

My Feedback: (3)

JP:

The only good reason I’ve found for kicking someone out of Club Saito is owning an OS engine. But if I were to enforce that I’d have to kick myself out too – I still have four of the &*^ things.

Huck:

The $100 offer still stands, and I do think it can be fixed for a reasonable price.

Bill.

DandGMartin

w8ye: Thanks for the link to the cylinders.
WR : Thanks for the heads up on the valve springs not fitting.

I've just spent about 4 hours trying to come up with part numbers for some other pieces: There must be a better way.
1. Engine gasket set: SAI8032B ?
2. Piston ring: SAI8009 ?
3. Valve springs SAI6574C ?
4. Cylinder head screw set SAI6514 ? I lost one when the engine failed so I checked with one of the remaining three to insure the threads were still good in the case (they were) but I noted that with the screw bottomed out in the screw boss it would just barely touch the top of the flange of the cylinder lugs, should these screws use washers or was the boss not deep enough or the screws too long?

I'll get the cylinder and parts ordered today (I see the cylinder is backordered)

You guys have been a great help Thanks
Don

huck328

My Feedback: (4)

WR - You have a deal. Send me a PM with your address and I'll ship it out. I kind of wanted to try a 150 anyhow. I turned the crank over last night for the first time and the compression is just like it was before the incident. It also has zero play when I hold the case and try to wiggle the spinner.

If I had more time, I'd give the repairs a shot, but right now I can't invest a ton of time to order parts, figure out how to disassemble and reassemble it, and continually ask you guys for more help - just to risk finding out that something else might be wrong that I can't diagnose and/or fix economically.

I will also include -
a slightly bent up slimline pitts (which I must say, took the crash Very well - the welds are so good, the engine head broke before the muffler welds would give out)
a slightly broken Cline regulator (I think the Fuel In nipple broke off)
the original box and instructions
the original muffler (only used for break-in)
a few oz of high quality Illinois soil (if you want me to leave it on there)

Please don't anyone else PM me offers... After seeing all that WR does for this forum, I would rather send it to him to be in able, loving hands where I can do no more damage.

William Robison

My Feedback: (3)

Don:

For your FA-80 -
SAI8032A engine gasket set
SAI8009 piston ring
SAI6547 valve spring set
SAI6514 cylinder screw set

Bill.

William Robison

My Feedback: (3)

Huck:

If you’d like, send the spinner too.

Address in separate note.

Bill.

loughbd

Bill,

Since you have 4 OS engines and you say they are no good, Why don't you just end them to me. I would be happy to be saddled with them

William Robison

My Feedback: (3)

Bruce:

Three of my OS engines are the “Good� ones, they are steel cylinder with the lapped iron piston, one is a Max I 0.35, the other are the Max III 0.15 RC. These are all good engines.

The fourth is a 46FX I got intending to see how long the cheap nickel would stay in the liner, since OS said all the failures were misuse. Figured I’d be able tp tell OS they were full of it when it failed, I knew I wouldn’t mistreat the engine. Sad to say, it’s about five years old now, hasn’t peeled yet. A big disappointment to me.

Bill.

DandGMartin

WR
Again thanks for your help on the parts numbers. I have them ordered, now comes the patience waiting training. O well, quess I'll have to work on getting some OTHER type of powered plane going for the interval.
Don

loughbd

Wow, what a surprise. Your 46FX is just like the thousands of other OS 46FX's that weren't abused. Just like mine. Just like the thousands and thousands of cheap nickel plated FSR's, SF's, VF's, RF's, VR's, FP's LA's and all the other cheap nickel plated engines OS made. Don't forget all the Nickel plated Thunder Tigers, Magnums, Royals and all the other Chinese clones.

William Robison

My Feedback: (3)

Don :

You're welcome, but except for transposing the last two digits on the valve springs you had then right anyway. And Horizon would have caught that.

The suffix letters don't really matter, they'll send the latest versions.

Bill.

William Robison

My Feedback: (3)

Bruce:

Quote:

ORIGINAL: loughbd
Your 46FX is just like the thousands of other OS 46FX's that weren't abused.

Granted, many did not peel. But hundreds did without being abused. And not just the 46FX - other sizes shelled in that period too.

If you like them so much,I'll sell it to you for the price of a Magnum XLS46.

Time to put your money where your mouth is, Bruce.

Bill.

loughbd

Now why would I buy a used engine from you for the price of an inferior new one? I wouldn't waste my money on any Magnum, Taiwanese or Chinese. They are nickel plated too. Why would I buy one when I already have a couple OS46FX's. Why would I believe you when you say there is nothing wrong with it when you are wrong on so many other things. Things like saying the FSR's were all true ABC and that the Magnums are true ABC and most of the other OS and Magnums are true ABC when they are nickel plated and have ALWAYS been nickel plated. Nope I'm quite happy with the HUNDREDS I already have. I might give you 25 bucks for it. I can always use the parts in my engine repair enterprise. You should jump at that price knowing that YOU know it's going to flake and be worthless one of these days.

By the way, don't you ever read Baxter's statements about OS46FX's. He says exactly the same thing I do. The number of flaking OS45FX's compared to the total made is negligable. The percentage is so small as to statistically a non issue. Of course just because he is the Tower rep and assumed expert on the subject, he really knows nothing and is lying to all of us.

olstoney

My Feedback: (19)

Gentlemen,
Why do we have a dialogue going on here about 2 stroke OS engines in the Saito Club thread [>:]? I have a NIB 46FX sitting on the shelf. As soon as I can get someone to buy it for $100.00 which is less than what I paid for it I'll sell it. Seems like the going price these days is $75.00 on that other auction site. I'll keep my 61FX as well, it has performed flawlessly in a trainer that I have owned for years. That engine has had the sleeve and piston replaced twice under the warranty. In all fairness running 15% Cruel Power without any added castor probably created some of those problems. Since switching to Wildcat 15% syn/castor blend never a lick of trouble. Imagine that .

rajul

My Feedback: (58)

Yeah, let's get back on track here. Saito discussions only please.