Jesse Open

Pretty

Navy_Flyer

Need help with a new (to me) Saito 125a. Came with a plane I bought - ran perfectly for one tank of YS 20/20 fuel and a 16-6 APC. When test running a second tank, it froze up solid. No warning - and it was rich running. Sent it to Horizon, and they said the bearings were toast. They replaced the bearings, the crankshaft and the connecting rod. Fast foward - runs beautifully now, ticks over on idle about 2200rpm reliably and the transition to full is instant, no hesitation - problem is, I can't seem to get any more RPM out of her than 8250-8400. Max RPM is with about 3-1/4 turns out with the high speed needle. If I lean any more, it sags and I don't want to fry it. Very slightly rich, about 8250 rpm. I tried a MA 15/8 and it turns about 8050. A MA wood 16-6 I can only get 7800. All of this with YS 20/20 full synthetic fuel. Ideas? Is it just needing more time/fuel runs?

N1EDM

My Feedback: (2)

Jesse Open,

I've heard of the 'Specials' but never found out what made them so. Can you let us in on it???

Thanks,

Bob

Glowgeek

Here's some prop/rpm data I pulled from one of my FA-125 engines a while back.

Fuel: 15% Synth/2.5% Castor, 15% Nitro
Props: APC Sport
Glow Plug: OS-F
Valve clearances: . 0015"-.002"
Temp: 78°f
Humidity: 58%
RPM is peak sustained for 30 seconds minimum
HP is calculated

FA125
16x8 (8050) 1.969 HP
17x6 (8370) 2.116 HP
15x8 (8940) 2.083 HP
16x6 (9000) 2.064 HP
14x8 (9960) 2.186 HP
15X6 (9960) 2.161 HP

After reassembly of these engines a period of run time is needed to seat a new ring, or to re-seat a used ring. Things may improve over the next gallon or two of fuel. Check your valve clearances before running again.

1200SportsterRider

Here are my numbers for the 125-a, on 10% Wildcat with 18% full synthetic lube:
Max minus about 50 rpm. Idle, as lean as possible. Saito 1.25-a MA Classic 16x6 10% 9,025, idle= 1,650

125-a with extra velocity stack for Captain Crunch.

Jesse Open

Hello Bob,

The 45 Special version was not imported by the US distributor so they are not commonly seen here. The original 40 and 45 as supplied were in a fairly soft state of tune.
The "Special" version came supplied with a hotter cam and revised cylinder head. The carb was also changed, losing the 90 degree elbow at the inlet. The inlet pipe and carb mount took on the style of the new series parts.

Like a 45 that was hot-rodded with some parts from the new FA-50. A little preview of the newer Saitos, yet to come.

acdii

And those engines were sold by SIG at that time!

Jesse Open

Do you mean Sig sold the 45 Special?

acdii

Maybe, they were the US retailer for Saito back then. I can dig up an old catalog and see what they sold.

Jesse Open

From what I recall, working at the LHS, the 45 Special was not offered in the USA. I had a friend bring me one from his travels in Germany.

vertical grimmace

My Feedback: (1)

When was the 220 discontinued? I really was not paying attention. Anyone know why?

1200SportsterRider

April 18, 2022

To all Tru-Turn loyal customers Worldwide;

Tru-Turn is suspending manufacturing in consumer model hobbies as of April 2022.

Since 1985, Tru-Turn has remained the highest quality and best performance of any R/C Aircraft Spinner, Prop Hub or Prop Nut available.

We are thankful for our over 35 years in the hobby working with some of the genuinely best people on the planet. Through those years, the hobby has dramatically changed but the people haven’t!

To the Weekenders, Competition Pilots, Builders, and Designers throughout the World – we thank you all for allowing us to offer our high precision American workmanship to this fantastic group of people sharing a common interest in flight.
• ROMCO has ceased manufacturing of consumer level components.
• We will continue to offer available inventory & modifications through Jun 30 2022.
• Items available after June 30th will be offered from finished parts inventory only while supplies last.

Tru-Turn is a registered Trademark of ROMCO Manufacturing Inc. whose likeness,
designs, images and use will be vigorously protected in perpetuity.

• ROMCO must focus all manufacturing capacities on domestic Industrial, Aerospace, Commercial UAV and Military production.
• Additional discounting is not offered at this time.

It’s worth repeating… We are thankful for every one of you and the all the
fun throughout our years in the Hobby Industry!

ROMCO Mfg Inc * Home of Tru-Turn Precision Model Products
281-479-9600

Glowgeek

gassers!

the Wasp

My Feedback: (1)

the first thing to do is to check the Rocker Arm/Tappet lash!
as "GlowGeek shows the clearance specs in his reply^

Jim

the Wasp

My Feedback: (1)

Dave, check out this link!

Jim
Saito FA-130T Keleo Exhaust - RC Groups

FlyerInOKC

My Feedback: (6)

Well that sucks bigtime!

Jesse Open

Guess I will just continue using these.
https://www.dbproducts.com/store/vortulti.htm

Twenty plus years now.

FlyerInOKC

My Feedback: (6)

Has anyone here ever run a 3 blade prop on a FA-82? I'm looking for a recommendation for a TF P-39 and they don't look right with a 2 blade prop.

the Wasp

My Feedback: (1)

LOL guys, is there a glow engine test stand sold inside the USA that is large enough to hold a 120 size engine? I have been searching, I can't find one.

I found one that says "Mayatech" on it but, A) no specs on it's size, and, B) being shipped from out of the country there are reports of it taking months to be delivered.

Jim

FlyerInOKC

My Feedback: (6)

Try this one I think Ron still makes them.

Glowgeek

The generally excepted rule when going from a 2 blade to 3 blade prop is to reduce the diameter by 1" and keep the pitch the same. Alternatively you can keep the diameter the same and reduce pitch by 2".

A healthy FA82 will spin a Master Airscew 14x6 or 13x8 at right around 9100 rpm on 15% nitro. The P-39 needs pretty good speed to fly scale so a 3 blade 12x8 is where I would start with that engine. Expect longer takeoff rollouts than with a 2 blader.

The Top Flite P-39 builds to between 8 and 10lbs and the recommended engine size ranges from .61-.75 cu. in. 2 stroke. An equivalent 4 stroke to power it would fall in the .82 to 1.00 range. It also is not what I would consider a lightly wing loaded plane. If I were determined to run a 3 blade prop I would seriously consider a Saito 100, Saito 91 minimum. But that's just me Mike, I like having power to spare flying warbirds.

1200SportsterRider

https://www.towerhobbies.com/product.../MAS1360T.html

13 x 6 great choice, maybe a little on diameter.

FlyerInOKC

My Feedback: (6)

Thanks guys!

Monty Python

Or...you could just start the engine, problem over

Glowgeek

Yeeeup.

Hello Pete.