JWN

My Feedback: (42)

I currently own one Saito FA-30 NIB that was bought for a sport scale, crop duster look alike, ultra-lite. My previous experience with them was a very early production FA-80 (high compression) that was a real power house. I wish I still had that engine as it would pull a 6.5 lb. Cap 21 straight up for as long as there was fuel in the tank (long after it was OOS).

They are great engines. I wish I owned more of them and had the time to fly them.

William Robison

My Feedback: (3)

[b]John:

I've added you as number 47.

My favorite is still the ABC version of the FA-120 engine. But every one I'm able to get now has to be bought used, current production is AAC. At the very least they seem to need bearings. They all get new valve springs as a matter of course.

Bill.

JWN

My Feedback: (42)

Bill,
I read through a couple of pages of this thread and saw your comments about the velocity stack. Because I'm too lazy at this very moment to check Horizon's site, do they make such an animal for my FA-30 and if so, what should I expect from installing one?

William Robison

My Feedback: (3)

[b]John:

Sorry, no stacks from Saito for the small block engines. But they aren't hard to make.

I'm working up a thread with illustrations on how to knock one out, I plan on doing one for the big block engines and one for the mid block. Your small block would be the same as the mid block except for the smaller size.

Two reasons for the thread. One is that Horizon is sold out of the mid sized stacks, And two, It's an easy project to work on when it's too dark to fly.

Bill.

JWN

My Feedback: (42)

I look forward to seeing how to make one!

Timthetoolman1

My Feedback: (6)

Hi Bill,
It has the removable cover. When I first ran the engine I saw bubbles coming from the pushrod tubes.

I won’t get a chance to work on it till Wednesday but my war bird nosed over on take off so there may be some contamination so this would be a good time to disassemble it and replace the worn parts. It has really good compression but the first time I flew it I had no problems tuning it but this last time I couldn’t really find the right spot. It used a lot of fuel too. I ran out of gas in probably 5 minutes. There seemed to be fuel dripping from the cowl so I need to check my fuel lines or it could be the pushrod o-ring.

I didn’t notice any fuel leaking anywhere else. Come to think of it one of the pushrod tube rubbers has a crack in it. I squirt after run oil through the breather tube so I know it’s fine (I didn’t do it last time because I think there is dirt in the line). The engine LOOKS lightly used but there is a lot of fuel on the engine for just 3 very short flights. You can see how the fuel just soaked up the dirt![:@]

Timthetoolman1

My Feedback: (6)

Here's my Saito 91. It is flawless so far
I had to make the fiberglass filler under the engine because it was wide open letting too much air in. I could have made it flat but I like the recessed look.

William Robison

My Feedback: (3)

[b]Ranger:

If the compression is good and the bearings aren't noisy, don't take the engine apart.

If the compression is good and the bearings are noisy then don't pull the piston out of the cylinder when you take the cylinder off the case.

Bad compression and noisy bearings, then you have permission for a complete teardown.

Seeing the picture of your FA-120, it really can't be that old. It has not only the AAC cylinder, it also has the high tappet guides and the late type cast muffler just barely shows. I doubt it could be more than five years old, or around that at most.

It would not surprise me, if you showed the right side of the crank case above the mounting lug, to see "120S" in gold letters on a black background.

It's possible you're misjudging the engine. Remember the FA-120 is the runt of the litter when you get into the big blocks, it's the smallest of all, it's bigger siblings now go all the way to the FA-220, and even the FA-180 is not much bigger than the 120. So you might just be expecting more than it has to give.

Fuel burn: I see you have the intake stack on your engine. Adjusted properly you should get at least 13 minutes on a 16 ounce tank, and that's assuming full throttle the whole time. With "Average" power settings 16 ounces will give 20 minute flights. Truly, it's all in the carb adjustment.

Don't fret about the leakage from the push rod tube, you probably won't see any when you get the engine dialed in. I would suggest a close inspection of the carb and intake pipe, check carefully for any leakage there. Set the valves, my recommendation is set them both to 0.002" to get the best performance.

Then quit worrying, and fly the plane.

Bill.

Timthetoolman1

My Feedback: (6)

Yep!

av8r1

Yes, that is confusing. I wish Horizon would put more details on their web site about the products, but like you said I know I can just call them to find out. I've done that before and it was pretty painless to get the answer I was looking for, which by the way was how to turn the carb around so the needle valve and throttle cable would be in the same place as they were with the 2-stroke I was using before. That's a very nice feature of this engine! Saved me a lot of work.

Thanks for the info on the part numbers.

Timthetoolman1

My Feedback: (6)

Good. I knew the engine was good by no bearing noise and REALLY good compression

Timthetoolman1

My Feedback: (6)

My gosh Bill, you figured out I'm new just with one post.

I got the Saito 91 because I couldn't tune the ST 90.
The ST 90 was in the P-40 but I wanted the Saito 1.20...did some trade'n and got it for just about free.

Shed some light here, when I tune the 90 I can definitely tell where it is just rich of peak but I really can tell anything on the 120. Does that come with time or should I use a tach each time? The first flight I had with the 120 it flew excellent. You know, I think my problem is that I'm getting them way too rich. What's the best way to tune it? Lean it out and pick the plane up nose high and see if it dies?

Bill, thanks for your help. Some times I get frustrated because I'm so meticulous that I over think the engine every time.

Ernie Misner

Bill, what' your oil of choice for dribbling down the valve grear?

Thanks again,

Ernie

Texastbird

I've been following this thread to see where it would go, and now I decided to jump in and ask about a Saito 150 I got from the estate sale of a fellow flyer awhile back. It has the long muffler with little holes drilled around the circumference of the outlet. And on one of the mounting lugs there is the letter "B". I think he had parked it because it had no compression when I got it but a quick valve adjustment and oiling restored the compression and it started right up on the test stand. Any of the experts care to comment on the age and any characteristics of this model? And, what nitro % is appropriate for this one. Thanks,
Tim

Fuelman

My Feedback: (6)

Would I qualify for Saito club membership?
I currently have 1-40, 1-72, 1-91, 1-100, 2-150's, 4-180's.

Only the 40 is vintage, the 150's are the higher compression ones, the rest are current.

Ernie,
My oil of choice is any of the air tool oils for what you are intending. A fuel with castor in it helps a lot in preventing rust and corrosion inside the engine.

Texastbird,
Both my 150's are the same vintage as the one you describe. I have used 5% to 15% fuel in it with great success, they did not like anything higher than 15%, but preferred 10% fuel in my oppinion.

Hobbsy

My Feedback: (102)

I have one of the 1.50s like Brian has and can safely say that you can't be wishy washy with it or you'll get whacked in a hurry but they sure run well. As Brian say the high compression ones run great on 5% nitro and they are not fussy about the plug.

Texastbird

Fuelman, thanks for the advise on fuel, So this is a higher compression engine than the current models? I have only test run it on 10% so that's what I will run it on.

Hobbsy

My Feedback: (102)

Texas, is your 1.20 black with chrome rocker covers? thanks

Hobbsy

My Feedback: (102)

Going back to the stack discussion, the .30 sort of has a cast in velocity stack in that the air inlet to the carb is conical tapering down as it goes toward the spraybar and is approximately 7/16ths inch in length. For the carbs lack of sophistication it sure works well.

William Robison

My Feedback: (3)

[b]'Kay.

48 Texastbird
49 Fuelman

Ranger:

What a tach does for tuning a four stroke is force you to wait for the engine's reaction. If you go slow, give the engine time to respond to a needle change, your ear works fine. The engine will usually be five to seven seconds behind you, learn to wait for it. Remember this is for a tuning change, not throttle response.

Ernie:

My oil of choice for pre-lube and after run is ATF Dexron. Costs a buck a quart instead of $4 for two ounces in a bottle that says "After Run Oil" on it. And I can't tell any real difference.

Texastbird:

The muffler you describe was supplied on the original FA-120S, the one that was a true hot rod. It was mid to late 90s. The "B" on the mounting lug is supposed to identify the production variant, allowing the correct parts to be selected. Don't put any faith in it. I have two FA-120 engines with the same code letter, they are different to the point of using different bearings on the crank.

Fuelman and Hobbsy have good notes on the nitro content, My personal preference is 15% with a castor/synthetic blend oil mix.

Hobbsy:

Granted, the FA-30 has a bit of flare as delivered, but how do you attach an air filter? Make an external stack, that's how.

Bill.

Texastbird

OK, Bill, so is the long muffler correct for my 1.50 or has it been changed out? In terms of performance is there any difference in the various styles of mufflers that Saito has equipped their engines with?
Texastbird, #48 [8D]

William Robison

My Feedback: (3)

[b]TT:

The long muffler can't be called either right nor wrong. It's just one of the types that Saito has sold for the engine.

Japan has much tighter noise standards than any of our organizations here, if it weren't for that I think Saito would probably still be supplying the engines with straight pipes. What I've seen over the years looks to be a continuing development of lowest production costs along with minimum noise.

The really old ones had just that straight piped with the end swaged to a smaller diameter outlet, giving a little muffling. Then there was a one piece muffler and pipe that didn't stay in production long, probably expensive to make. Then came the machined cylinder which is still used on the small block, it's the one everybody likes.

Your "Long" muffler came as in intermediate unit, it first came on the "True" FA-120S. This engine had a completely different cylinder and intake pipe from all the other big block engines, a really hot cam, and that long free flow muffler.

Some people really liked the first 120S engines, but more fussed about the noise and the rough idle. The sharp exhaust rap and the cobby idle were resulting from the radical valve timing, Saito went back to a milder cam, the muffler replacement was a production change.

Then came the "High Cam" engines that looked the same except the intake pipe and they went back to the cylindric muffler for a short time, until the entire line (except the small blocks) got the current cast muffler.

The only Saito I know of currently using a really hot cam, timing similar to the early 120S, is the FA-72. This has two results. Fussing about the idle and praising the power. It's small enough that people don't seem to fuss about the rap in the exhaust.

Enough about mufflers. Here's a composite of five different ones, there are more not shown.

Bill.

Genesis_twin

I've got a 182TD, but it's not in a plane. Can I still be in the club?[]

Hobbsy

My Feedback: (102)

Very cool GT.

WR, is pic #4 the big bazooka muffler like is on my 1.50?

UltimateFlyer120

My Feedback: (5)

Genesis Twin it's not a plane but I think it might fly!!!