SrTelemaster150

Put a 16 X 8 on an FA-125 W/GI & it will spit the prop in less than 2 minutes @ WOT. Put a 15 X 8 on a 115 & I'll bet it will pull as good as the 125. I had to use the 15 x 5 from my 91 on the 125 I worked with because it would not pull the 16 X , even W/CD.. It pulled just 300 RPM better than the 91 W/the 15 x 5..

The 125 is 36gr heavier, 7mm taller & 4mm longer than the 115.

YellowBlueBird

Set the low speed needle today. A friend loaned me a tank of his 20% nitro. Yes it ran better after the pre breakin tuning. The core problem remained It goes rich when rolled inverted. In the next few weeks when time permits the engine will be reinstalled on its side.

Thanks for the advice guys.
Jerry

Hobbsy

My Feedback: (102)

Common sense says that if the 1.25 spits the prop, it was set too lean. If there were a YS engine being discussed in this mix the YS fans would claim the 300 rpm was the YS stomping the other brand.

Jerry, is your LS needle in about this far.

SrTelemaster150

Spitting the prop with the PROPER HSN mixture means the engine is not capable of sustaining the load & is over heating.

What don't you understand about the difference in displacement between the 125 and the 91?

I can usually gain 300 RPM just by converting most Saito single cylinder engines from GI to CDI. I would think that a 37% increase in displacement would yield more than 300 RPM.

When I get an FA-115 for my 1/5 scale J-3 Cub I'll be using a 15 x 8 prop. We'll see what it is capable of.

Here's the thing, the 115 will fit within the cowl W/only the tips of the rocker covers showing. The 125 will not. Most of my planes are scale & I can't stand the looks of a cylinder sticking up above the fuselage. I always mount inverted of horizontally.

Rudolph Hart

I love it when you get fired up dave,puts a good shot of life in you

Rudolph Hart

Stop flying the aeroplane on it's side and all will be well.

Hobbsy

My Feedback: (102)

You're a funny guy Pete

Dan, I understand the difference perfectly, the difference is .34 Cu. In. If that happened on my 1.25, it would only happen once. From that time forward I would set the HS needle to avoid that eventuality. You can't win a fight with an engine, it will have it's way every time.

I_Fly

No. No. He needs to start flying the airplane on it's side!

SrTelemaster150

If one has to set the HSN richer than optimum power in order to keep it cool, the engine is over loaded. I couldn't get the FA-125 to pull a 16 X 8 even W/CDI! At WOT it would eventually overheat before it would drain an 8oz tank.

I'm not the only one that has issues W/the FA-125, just go back through this thread. It is far from the best example of Saito engineering.

blw

My Feedback: (3)

This may be a normal trait with only a gallon run through the 125. IMO, the 125 takes longer to break in than any other Saito. At best, you are halfway there right now. Some people will say it's already broken in, but you can easily proof that wrong by tuning it dead solid perfect and see how long it holds. It won't more than a couple of tanks of fuel. Also, you can track fuel economy and it will show a bit better after the next gallon of fuel.

Like Hobbsy said, it's a torquer but it will haul the freight too when you have it propped right and it hits the power zone. Mine is on a 90 size pattern plane and it shot it up vertical lines like a missile. But, mine is a little finicky about being tuned just right. I'm talking about the low speed needle here. Get that right like Hobbsy pointed out and you will have a powerful engine on your hands.

Hobbsy

My Feedback: (102)

My little .30's are going to match in about 3 hours. I used NAPA Gloss Black Engine Paint good to 500 degrees. It's oil and antifreeze resistant.

FlyerInOKC

My Feedback: (6)

It's got bunny ears!

Hobbsy

My Feedback: (102)

It does for sure, it's now a close match to it's older sibling. The new one has an E on the right lug the old one has an A, it was one of the first shipped by Horizon.

FlyerInOKC

My Feedback: (6)

Looks good!

spaceworm

Very nice Dave. What differences have you found between the "A" version and the "E" version? It will be interesting to see how they perform against (or with) each other. You are planning a twin for them, right? Is there a way to reverse the rotation of one of them to power a twin with counter-rotating props?

Sincerely, Richard
AMA 861960
Club Saito #635; Saito 56, 100, 120abc, 130T, 180; YS F 120;

FNQFLYER

See old fart these yanks really don't read our posts. I regularly run 15x8 and 16x8 props on my 65 with no problems. And for good measure I run a variety of props in those sizes with different profiles, composition and shape. And I have no problems at all. My "new" in box 30 is still there but I am on the trail of an open rocker version just to have. Just got to convince the "wood duck" that it is no good and an OS or equivalent is better and that I can give it a good home. Our state comp had more competitors than the same event at the Nationals which I think annoyed more than a few people but age and gile will win out every time.

YellowBlueBird

Could still go in a bit more to match the image. OK so may not be ready to really lean it out. I will take it out again Sunday run two more tanks and then readjust using tack.

Hobbsy

My Feedback: (102)

Hey Richard, I haven't run the "E" version yet, I didn't want it to have oil all over it before I painted the cylinder. Even at that I sprayed it with NAPA Brake Kleen. Then dried it on a heater that I certainly didn't need to use today. I'll let you know if anything shows up. Yep, they're for a twin, this 50 Caliber by Eureka Models.

Thanks OKC.

FNQ, we do read your stuff, it's just that very few run .65 sized engines with 1.50 sized props.

Keep us posted YB.

Rudolph Hart

If you are going to fly a cub with the 115 a 16x6 would give more than scale speeds,and prop torque when you throttle up.I use a 15x8 mas classic on the midget,it's quick and you get a sonic boom off the prop tips every now and then

Rudolph Hart

Jerry most modellers i know are honest enough to say they get a bit wary when first leaning off a new engine,follow dave and barrys advice you won't go wrong.You're still being a sissy but

Trev get used to the fact that down here we are just colonial sodbusters who like to tune and run saito's too,except popey who does'nt and is'nt i mean dave's photo's are in focus now,that's important,and he's done a decent job of painting his new 30 to match the other one.Do you reckon he's noticed that some lowlife has snuck into the engine room and stole the carby,exhaust,prop and spinner off the new 30?

Hobbsy

My Feedback: (102)

Yeah Pete, it's going to be tough scrounging up another Graupner 10x5, I'm hoping I have two of the Bolly 10x5.5 or 10.5x5. We'll see.

the pope

Now now , what you think I just visit here to cop crap from the likes of you and rack up naughty points from the mods ? You holden gemini drivers are all the same ! Cheers the pope

YellowBlueBird

Jerry most modellers i know are honest enough to say they get a bit wary when first leaning off a new engine,follow dave and barrys advice you won't go wrong.You're still being a sissy but

Hay, Old Fart, its best to be a sissy than have a burned out $400 engine from going to lean. The brand that I have been using never required more than a quarter turn on the low speed needle to get it dialed in. That's why I came here asking questions. Hope you don't freeze up over there. Took my sailplane out yesterday. Lots of thermals under those big white tropical clouds.

mo lata

Jerrry

FNQFLYER

Whats wrong with Gemini's?? I had a very rare twin cam 1800 with a 5 speed g/box to play with rallying in the Victorian Alps when I was a lot younger. On props what I am trying to say is it is engine management that is the problem not the prop size. Some props are clearly wrong for the application they are being used for and all are subject to the "nut" operation the fuel supply. On football, pope have you noted that the international gentleman's game is being played in the heart of your beloved aerial ping pong and whats more will get crowds in excess of your AFL matches at the same venue (already presold tickets) expect mind you for your grand final.

FNQFLYER

With running the advice I got from Gen Saito was to run the engine as rich as it would take and lean it off as it indicated it needed until you achieved factory optimum. The first hour of running should be on the bench should be with a "heavy prop = APC or master airscrew, NEVER a wooden one and once a reliable engine run range (throttle response) was obtained fly it in an "old a/c" until you are comfortable with it that is run in to your standards. Always worked for me and my mates.