TimC

Phillip, with a limited test, I found a slight rpm increase with the stack. When I added a fine mesh filter there was a drop of the peak rpm (several hundred).

gjeffers

Rajul, im getting around 8800 with the 16.5x5, its not a "W" prop, but the spoolup is fine for the ucd 60 at only 8 lbs with the 125, flys it real good with plenty of power,(kinda why i like the light saitos that are a little over powered).and i can buy the cheaper 10% fuel, i found a hobby shop in Bakersfied that sells it to me for $44 a case, great deal

jb86

My Feedback: (8)

i have an old os 40fs surpass, was sitting in a box since about 1990. thought it would be a good practice to rebuild. i got the harry higley engine book and followed it to a "T", great explainations and pic's of every step. also rebuilt a 46 sf/ringed; ring/sleeve, bearings
there is no mention of heating to remove the sleeve. on my 40fs (and 46sf), after removal of the head, i turned the crank up and down a few times, it loosened and i was able to lift it out, maybe a sharp object to get under the lip of the sleeve.
the wrist pin is not at all difficult to remove. i tried a few things, it is recommended to stab the white plastic w/a t pin, then slide out. i'm sure mine was sticky because of age and varnish. i screwed a hex head servo screw into it w/an allen, then grabbed it and pulled it out. replace the same way, i did use a new one.
main bearings, no problem. the outer cam bearing in the cover was easy enough to heat and tap out. the inner cam bearing is next to impossible to remove (atleast mine was frozen). the book says to heat the are, then tap the case against a paper pad or something. first off, it is impossible to hold the case while heating that area (even gloves get too hot), and it's hard to bang it against that side. i said screw it, i cheated and paid $37 for a new case. i have heard that sometimes, they use some kind of a tool w/a lip, to reach under the bearing and wedge it in, then a slide hammer to tap it out (after heating it). new valve springs and retainer, ring and sleeve and bearings. i was proud of myself when i started it and ran well.
cam gear alignment; the cam gear is a bevel type tooth. meaning, when you slide it back in, it will roll forward. so, you actually align it one tooth off, so that when slid in, it will align as in the picture. took me about 4 tries.
then just set the valve gap.
jon b

tkeeg

Hello All,

I am a new Saito engine owner. I bought the Saito FA100, (my first 4 stroke engine), brand new sealed in the box, from a member of my flying club. I am putting this engine in a 3D/Pattern Plane called the Quest. The fuel tank is mounted back at the Center of Gravity, about 10 inches behind the engine. The engine needs to be mounted inverted to fit in the cowl, resulting in the center line of the fuel tank being about 2 ¼ inches ABOVE the carburetor. Unfortunately there is no way to get around putting the fuel tank or the engine in a different location.

I tried running the engine without a Perry pump at first. It initially seemed to run alright, but when I make the plane do a straight up vertical climb, the engine cuts out. Members of my club stated that I needed a Perry pump since the fuel tank is so far behind the engine. I hooked up a new model Perry VP-30 pressure pump and attached the pressure line between the pump and the crankcase breather. The instructions for the Perry Pump did not say anything about putting in a tee, so in my hook up the crankcase vent is no longer exposed to the atmosphere. The tube from the crankcase vent goes directly to the Perry Pump with no outlet for the crankcase oil to drip out. (I did not know any better until I read an article online about using a tee to feed the Perry Pump and to vent the crankcase). Since doing this hook up with the Perry Pump I got the engine to run briefly, but before I was able to finish all of the adjustments, It cut out and I can no longer get the engine to fire. It cranks and cranks, but just will not fire. I tried to start it for about 2 hours with no luck. I checked the glow plug and it is working perfectly. If I take the fuel line off of the carburetor input there is fuel being pumped through the Perry Pump as I crank the engine, however is seems like the fuel is not somehow just not getting into the carburetor. Could all of this be because the crankcase vent is not vented to the atmosphere anymore? More importantly, could I have damaged this engine by trying to start it with the crankcase vent not being exposed to the atmosphere? I did not have a problem with Hydro Lock and there was never a problem with the engine being hard to crank.

These symptoms remind me of when I couldn’t get a 2 stroke engine to start one day. It would crank & crank but not fire. I finally saw that I had forgotten to take the paper towel plug out of the muffler that I had put in to keep fuel from dripping in my car the last time I had flown that plane. As soon as I removed the paper towel plug, the engine fired right up.

Furthermore, if I am ever ale to get this engine running properly, is there a way to prevent fuel from siphoning out of the fuel tank and flooding the carburetor when the engine is stopped?


Anyway, if anyone has some advice for me I would greatly appreciate it.

Thanks,
tkeeg

w8ye

My Feedback: (16)

Yes, throw the Perry pump away and use a Cline or Iron Bay demand regulator next to your carburetor. Use muffler pressure and a check valve to pressurize your tank. Leave the crank case vent open to the atmosphere.

cracker

Saito 72

I've been running one of these in my Sig SE for years and have developed a problem. The engine will not run at all and it feels like there is very little compression. I have adjusted the valves and have the same result. Any ideas or should I send it back for repair? I have never disassembled this engine other than taking the plug out and inspecting the cyl head, all looks normal. The engine does try to fire occasionally when trying to start. It is getting plenty of fuel. I'm guessing either a bad valve or shot ring?[&o]

w8ye

My Feedback: (16)

When you are turning the prop by hand to feel the compression, the carburetor must be at least half way open. If the engine cannot get air, it will have no compression.

The 72 is bad about the intake tube leaking at the head joint

tkeeg

Thanks w8ye for your response.
Today I took another look at the engine and noticed that there was almost no compression. I took off the valve covers and found that one of the valves was frozen solid. Guess that's why it wouldn't start. I'll have to send it in for repair, but I still don't know what I did to cause that problem.

w8ye

My Feedback: (16)

I have managed to free these up with a little solvent on the stem from inside the port. Then by pushing the valve back and forth.

The valve most likely has congealed castor oil on it?

tkeeg

w8ye, Thanks for your information.
Do you know if there is a website that gives instruction/diagrams on taking engines apart to fix or examine them.
That would help me since I've never taken one apart before. I'm mechanically inclined with most things, it's just that I've never seen anyone take one of these engines apart before.
Thanks,
tkeeg

w8ye

My Feedback: (16)

There is a wealth of information on this forum. Start at the beginning of the club Saito thread and keep reading.

Look on this site for bearing replacement technique

http://www.rc-bearings.com/

ultimate-pilot

Hello people,

I just bought a Saito 72. I want to build it in an ultimate biplane 40 to fly 3D. But which prop will give me the most power?

Greetings, Ivo

w8ye

My Feedback: (16)

If you intend to do regular flying the 13-6 would be best but if you intend to do 3D then you will need a 14-4

Ernie Misner

I'm asking this for a friend who has a new Saito 100 for his Ultra Stick...... Which props should he try?

The APC 14x6 ? (can only find this in the expensive Pattern prop at Tower???) MA 14x6 instead perhaps, or the 15x4W prop?

I've been working on the digital photography lately and haven't been here as much lately.... but DO have a new Reactor to build for my Saito 82...:-)

Thanks loads and hello to everyone,

Ernie

w8ye

My Feedback: (16)

For regular flying a MAS 14-8 would be fine.

A MAS 15-6 will make a nice buzzing noise on a fast flyby. Will also give better vertical

N1EDM

My Feedback: (2)

To go along with what W8YE says, every once in a while Bill Robison condenses all the information here and makes a file called Saito Notes. I have a copy of the November file on my club's website. Head up to

http://www.ssrcc.org/Secret%20Page.htm

and download it. It'll have all the information that W8YE has been talking about, and more.

I hope that this helps,

Bob

Hobbsy

My Feedback: (102)

Stock Muffler and APC 14x8 ==9,373 Pic. #4

TurboHeader and APC 14x8 9,511 Pic too dark, not readable.
Pic. #5 TurboHeader and APC 15x6==============9,428 rpm
Pic. #6 Stock muffler and APC 15x6=============9,225 rpm.

Ernie, here are some numbers from my 1.00, as Jim mentioned the 14x6 would be a little light for the 1.00

NM2K

My Feedback: (14)

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


I'm not trying to burst your bubble, but I doubt that a Saito .72 will successfully hover a typical .40 sized biplane and still have the extra power to pull out vertically, if the model is a standard ARF that was not designed specifically for 3D when powered by a .72 sized engine. Nice run-on sentence. Sorry.

I would think that an .82 would probably be more appropriate, or a light weight Saito .91 or YS .63.

Let us know how you make out with the .72.


Ed Cregger

gjeffers

Ivo, if you can get the weight on it to come in at low end (5.5 lbs) it wont be to bad. but at 6.5 it will be a dog

buzzingb

My Feedback: (2)

I have seen a 72 fly a SIG Ultimate 40 profile and it will pull it well but as stated keep it light or you will know it. A 45 can barely handle this plane vertical as I flew one for 3 years with a 46 and it would go vertical but not like a rocket. YOu should consider the Boxer sold by Ohio Models as it a much better plane.

baddley

My Feedback: (1)

Hi

How are you guys doing. I have a Saito 91 that is mounted the Matt Chapman Cap 580. Has anybody had expierence with the flexible exhuast from Saito or any other kind of muffler extensions that will work for this engine. I would not like to have to make a cutout for my exhaust if i dont have to.

Thanks Scott

tailskid

My Feedback: (34)

I had one with a 90 degree bend and flex pipe....go to.... http://www.rcgroups.com/forums/showthread.php?t=444996 and you will see the set-up....just remember to hold, secure or fix the pipe near the end or it will break from flexing!

gjeffers

how'd that sound Tailskid?

blw

My Feedback: (3)

The .72 could hover a light model with power to pull out. People are doing it with Somethin Extras. But, the .82 would be a better choice.

tailskid

My Feedback: (34)

Very nice and quiet! Sure didn't effect it's power output IMHO...