William Robison

My Feedback: (3)

Member number 112 is now Vallhala.

I'll send you an engine if you'll send a tall blonde Svenska flicka back!

Haw.

Bill.

gjeffers

Bill, lets keep on topic now

while im here ill ask----- will the new 125 have a 14mm exhaust? and if so are there any headers for that size like the ones for the 182td's?

thanks Bill, (a blonde from sweeten, wow)

William Robison

My Feedback: (3)

Gary:

I've not been allowed to hold the FA-125a long enough to check much of anything, but here are the flex pipes and bracket in 14 mm size.

Flexible Muffler,14mm: SAI300T73B
Price: $36.51

Flex Muff w/Pressure Tap, 14mm: SAI300T74B
Price: $36.51

Muffler Bracket:SAI300T99A
Price: $8.25

Bill.

cart3192

I've got a TF P51D Mustang kit on the bench that's going to get a new Saito 125. Love the engines and I have the 56, 82A, 91, and 120... good stuff!

Kmot

My Feedback: (24)

Mr. Robison, a few questions if you don't mind?

When did Saito switch from the aluminum rockers to steel?

Are the aluminum rockers fragile? Should I consider switching to steel if running the engine in a model? (It's going in a boat and it will be watercooled)

What is your opinion of sealed versus open rear bearings?

Any reason to not lighten the cam gear?

Thanks,
Tom

William Robison

My Feedback: (3)

Tom:

I'm far from an authority on the open rocker Saito engines. What I've been able to find makes me think there was less than a year's production with the aluminum rockers, just a few hundred, and not many more with the steel rockers before they went to the enclosed valve gear.

Running the engine in a boat I don't think there will be any worry about the fragility (or not) of the rockers, unless you plan to run "White" water there shouldn't be any crashes to break them.

Curious about how you are planning to do the water cooling. Tightly wrapped tubing?

A sealed rear bearing is a sure way to ruin a cam shaft - with the bearing sealed how is oil going to get to the cam? Bad idea, worse even than running all synthetic oil.

Bill.

Thunderchild

Hello Mr Robison - another question if you please................

I have just purchased another beautiful little Saito, this time an 82a. I noticed in the manual (yes if all else fails read the bloody manual) that they say to avoid using castor becuase of the high exhaust temps in four strokes.

I have been religiously using 5% castor for years - have I done/risked damage?

Cheers from Down Under [8D]

William Robison

My Feedback: (3)

Tom:

Sorry, I missed one.

Lighten the valve gear? Why? Float rpm is already way above red line. But if you just want to make it pretty that's another matter. Shine it up, boy.

Bill.

William Robison

My Feedback: (3)

Thunderchild:

There must be an entirely different set of manuals distributed in Oz. I've heard from other Australian users that their books said synthetic oil only.

Our manuals here (USA) said for years that a castor blend was recommended for maximum engine life, the latest 2005 revision says use of castor is acceptable.

Personally, I wont run one without castor in the fuel. At least 3% castor, preferably 4%, with 15% synthetic. I like 15% nitromethane, the rest is methanol.
In other words, I think you would have made the error had you run without castor oil in your fuel.

Bill.

panzerd18

Maybe the engine manufacturers have noticed that synthetic oil technology has risen to the point that castor oil is not needed anymore?

NM2K

My Feedback: (14)

I haven't seen any evidence supporting this hypothesis.

Also, if there is an oil that eliminates the need for castor, but is too expensive to simply spew into the environment as a model fuel component...

Economy must enter into the equation at some point.

quint-rcu

My Feedback: (24)

Ten Saitos in the stable; 3ea - .91, 3ez - .72, 3ea .56, and 1ea 1.20

Now I have a question for the fellow members: I recently acquired one of the .72's with a dissasembled carb. I have replaced the gaskets and need to know a starting point for the idle mixture screw. Anybody know the initial factory setting for the idle mixture screw? (not the high speed needle valve)

thanks,
quint

William Robison

My Feedback: (3)

Quint:

Unless your FA-72 is one of the very first it will have a plastic throttle lever. The initial position for the idle adjuster is with the flat set from 1/32" to 1/16" below the surface of the throttle lever.

If you have the metal lever set the flat even with the lever face.

Arrow in the picture shows the location of the set screw holding the lever.

Bill.

Kmot

My Feedback: (24)

Bill,

I was afraid of that. Open rear bearings in the size I need have been difficult to locate but I finally got some cross referenced bearings to choose from (other brand engines).

As for fragility, I should have expounded my question. I realize crash damage would make them quite fragile, lol. I meant merely by running are they fragile and so was the reason Saito switched to steel. For reliability and long life. They certainly look prettier than the steel and now that I learn I have one of only a hundred ever produced I am ambivalent about running them.

As for lightening the cam 'gear' I was referring to the gear only. Not the valve train. I thought it might be a way to increase aceleration of the engine. Even though it would be hidden, I figured it would look trick too. At least "I" would know it was in there like that, lol... silly me!

The reason I am going to put this particular engine in a boat is to dissuade it from crash damage. That way I can run it, enjoy it, and not wreck it. I plan on either making a water jacket for it ala the rare OS FS versions; or a clamp style ala the electric motor style.

Thanks,
Tom

William Robison

My Feedback: (3)

Tom:

I would suppose Saito switched to steel rockers purely due to the expense, although a flaw in the casting could cause a failure in service; the cast/forged iron/steel rockers would be far less susceptible to such failures.

The wear point isn't the rocker itself, it has the steel pad on the valve end remember, but the rocker pedestals cast as part of the cylinder head. Even there the movement is so slight that wear is only a long term concern. When the pivots do get sloppy a brass busing installation is trivial. When/if you get to that point I can bush them for you, if you don't want to do it in your shop.

Warning about a boat installation: If you put the engine in a "Speed" boat there is the possibility of bouncing the prop out of the water, and if you do the engine rpm will go through the roof. The over-revving leads to valve float, valve float leads to extreme hammering in the valve gear, and that can break a rocker. Please take note.

Sealed or shielded bearing? No problem. The seals/shields can be popped out with no trouble. Next time you'll know.

Bill.

Kmot

My Feedback: (24)

Bill, It will be going in a slow scale boat. No worries about the prop unloading.

"pulling seals out of sealed bearings" Sometimes just can't see the trees for the forest!!

These are the only types of bearings I have disassembled for the last 25 years:



Tom

Airbike

My Feedback: (6)

Well, I'm not a member of club Saito, but I do have a pair of FA100's that'll be going into a Super Duelist when I build it. Yes, Bill, I haven't started yet.

On another note, I came across this on another site:

SAITO FA-125 AAC

http://www.horizonhobby.com/Shop/ByC...rodID=SAIE125A

Much lighter than the old FA-120 it replaces. Maybe its based on the FA-100 crankcase?

William Robison

My Feedback: (3)

Tom:

Nicebright shiny tapered roller bearings. They're so pretty they don't make me think of cars, but rather wheel bearings on aircraft.

--------------

quint-rcu:

You are now on the roll as number 113.

The more the merrier.

Bill.

William Robison

My Feedback: (3)

Airbike:

You are indeed on the list, you're number 114. You need to check the listing on page 27 of this thread. Of course I have to admit that when you made the post I had not yet put you on the list... Haw.

Haven't started building your Super Duellist? Don't feel alone, I think most of the kits we sold are still waiting to be built. I know of only one that has been completed, and I've still not heard of it being flown.

There are already a couple threads here about the FA-125a, and yes, it's an overbore of the FA-100, just as the FA-82 is an overbored FA-72 engine.

Bill.

av8r1

The confusion about castor may be due to the wording in the manual. My 2005 manual says:

Use of fuels composed
entirely of castor oil is not recommended.
A mix of synthetic-castor oil is acceptable
and can be found in the various fuels
described above.

The first time I read it I thought it said castor was not recommended but I didn't want to believe that so I read it again. I think the key word there is "entirely".

William Robison

My Feedback: (3)

Av:

As you said, the current (dated 2005) manual says "A mix of synthetic-castor oil is acceptable."

Attached is a scan of the older manual page.

Bill.

av8r1

Exactly. It's the first line that could lead to some confusion at first read where it says in the new manual "Use of fuels composed entirely of castor is not recommended." Same meaning in the old manual but slightly different wording in that it says, "The use of all castor oil ... is not recommended." Maybe that's why they changed the wording.

Thunderchild

Hi again Bill and hello to you Av,

You were correct in your first assumption Bill: The Oz manuals ARE different.

There is no misread as Av might be suggesting, the manual specifically states DO NOT use castor oil due to high exhaust temps. I do not have the manual with me at work (Sssh that's where I am at the moment - he he) but trust me, our manuals are definitely at odds with yours.

Cheers,

TC

tailskid

My Feedback: (34)

Maybe castor 'acts' differently south of the equator

Jerry

gjeffers

# 23 here,all i can attest to is that my 100 lost the rear bearings while useing all syn after approx 60 flights, and since using Bills advise of using castor about 7-8 months ago(approx 350 flights) my engine still runs like a top!!

thanks Bill

man this castor thing never goes away[&:]