Hobbsy

My Feedback: (102)

Hey GD, WR is wearin a big ole grin tonight.

blw

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And taking his pics........

sertac74

Hello, i have just have my first saito ever(also my first 4 stroke). The Saito 125a for my plane showtime 90 (hangar 9). I installed an apc 15x8 and a alu 65 mm spinner on it.

i may be late but i would like to ask if i had mistakes while break-in process.

First of all i installed everything to the plane and used 15% nitro with 18%oil which i have locally in my hobby store. I turned the High speed valve to end and then open it to 4.5 turns. I fired the engine and it run good for the first time after priming. I left the heater on it till the tank empty approx 8 munites. (after engine off the glow heater battery emtyed ) For the first tank i run the engine about 3500-4000 rpms constantly. After cooling process i run the engine with HS Nvalve turned 3.5 open and run to test if it runs without heat source. I run and the rpm had to be at 4400-4600 to run without glow heater. I take out the glow heater and run the engine at about 4600 for about 10 mins.

For the third run i turned the hsnv to 3 and run the engine and keep it run about 4000-5000 rpm for 3 mins. Than start to increase the rpm slowly to about 6500-7000s (short times). For the last run i start the engine wait to warm up than Turn the High Speed neadle to 3.5 (richer than 3rd test) turn again and test higher rpms slowly and in short periods about 8000s.

While i was in brak-in process the engine did not became very very hot but i test feel that it is about 3-4 times hot then my other 2 stroke engines. And at the end of the last run (4.th\high rpms) i mentioned that the engine is extrimely hot. Does this much heating normal?

Any comments will be appreciated.

Note: our climate is hot. Nowadays winter season is about 15-20 C degree. For Summer times it is about 33-39 C degree peak. I fly nearly zero to sea level. Costal area. For the break-in it was 20 C degree.

Capt Lou

Saito recommends about 40 minutes on the bench break in time with a gradual increase in RPM's which you seem to have done while running it very rich. This covers the high end setting of the needle. From your message, I can't tell if you met this time frame. The over heating at the end may be that you leaned it out too early. I recommend that you continue to run the high end rich a couple of tanks beyond 40 minutes. Once you have done that, then you need to adjust the low speed end of the carb. The factory setting for the low speed side is extremely rich so you will need to adjust this leaner. The low end is more trial and error so read the manual as to when this is just right. It is recommended that you break in the high end completely before adjusting the low end.

sertac74

I run the engine totaly about 30 munites.I will run the angine about 10-15 minutes more with rich settings. I aslo forget to say that the plane and my backayrd is very oily and too much smoke everywhere. Oils coming out from the exhoust with too much smoke.
After 1-2 more runs i may try to adjust the low valve and may i maiden the plane?

blw

My Feedback: (3)

Your engine is ready for getting the high speed and low speed needle valve adjustments. You can lean them out much more. Also, the engine is ready for some wide open runs once you lean it out more. It is good that you put time on it.

rlmcnii

My Feedback: (3)

sertac74,

It sounds as if your engine will be fine. If you get the HSNV far too lean the engine will not run at full throttle. If you still have lots of smoke and oil you are not too lean.

To set the HSNV, do as follows:

1. 4.5 turns out on the HSNV should be fine.

2. Run the engine at full-throttle. You must adjust the HSNV with the engine running at full-throttle.

3. Use a tachometer and turn the HSNV in, that is lean, until the tach shows maximum rpm. As you approach maximum rpm the HSNV will become sensitive. Turn it one click at a time and let the engine settle on its rpm before leaning the HSNV more. Do not lean the HSNV beyond maximum rpm.

Having accomplished this you are now ready to adjust the LSNV. On a Saito the LSNV is very important and the engine will not run its best unless you adjust the LSNV. It will run, but you will still be spraying oil and fuel all over your backyard. To adjust the LSNV, do as follows:

1. Start the engine and run it at 1/4 throttle, or a little less. You want a very fast idle speed.

2. Slowly turn the LSNV in, that is lean, and you will notice that the engine rpm will increase, the engine will be running more smoothly, and there will be less fuel and oil blowing all over your back yard.

3. When adjusting the LSNV you are looking for the leanest setting from which the engine will accept a transition to full-throttle without hesitating or stopping. (The following steps are how I finish setting the LSNV. Other people have different methods that undoubtedly work as well. Perhaps you will get to read some of those methods also.)

4. Slowly turn the LSNV in, lean, until the engine rpm just begins to go lower. You are now just a little lean on the LSNV. NOTE WELL: You will probably have to turn the LSNV more than you think you should. The LSNV is set very rich from the factory.

5. From this setting open the LSNV 1/8 turn and try to run the engine to full-throttle. If the engine stops, the LSNV is still a little lean. Re-start the engine, open the LSNV 1/8 turn and go to full-throttle. The engine will probably now go to full-throttle without stopping. If it does, that is very good. If it stops, the LSNV is still lean. If it has a very slight hesitation, it is just very slightly lean and 1/16 of a turn open may take care of the hesitation.
Again, you are looking for the leanest setting that will still permit a rapid, clean, and repeatable transition to full-throttle.

6. Once the LSNV is set properly go back to full-throttle and open the HSNV (this may just be one or a few clicks) to drop the maximum rpm by about 300. This will give a little margin of richness at full-throttle.

When all of this is accomplished, and it just takes a few minutes, you will notice that the engine is running much better and it will not be blowing oil and fuel all over your backyard!!

As you fly the engine you may need to make very slight adjustments as the engine gets some time on it. Remember: Adjust the HSNV only at full throttle. And, you may be able lean the LSNV a little as the engine is being used.

Do this tuning and go fly your airplane. Enjoy!

sertac74

Thank you very much. I am now confident that at the ground i need only one tank of fuel to complate the process. I will go through the way as rlmcnii adviced. The last tank at the ground will be for the adjustment purposes and since it is weekend tomorrow (off days ) i will do these works tomorrow and go flying. I will tell you about the process.
Tnak you again.

mike early

I received my GloBee Tach tonight. So I put the new 125 on a rigged test bench. I guess it was too dark outside, (overcast evening and slight drizzle), because it the tach just wouldn't cooperate. So I tried to find the max RPM by ear. Unsuccessful. It's a lot harder than I imagined it would be. I did get to measure the idle RPM at 2400. I would have guessed a lot lower than that. I will try again tomorrow when it is brighter.

I also was able to test for back pressure on my new pressure fitting. It was able to produce bubbles at least down to 5" depth. I was satisfied with that. I had mounted the fuel tank at a couple different heights in perfecting my setup. Even when the tank was significantly below the carb, fuel delivery did not seem to suffer

mike early

What is the opinion of flex pipes vs mufflers in terms of performance?

jaybird11

Cant find out what number I am ?I thought I joined six months ago!
Twist 60/saito 125,goldberg cub ann,saito 82,hot stick,saito 45,tango,saito 62.

blw

My Feedback: (3)

jaybird11- I looked all the way back and didn't find you listed, but you are now #579. Sorry if I overlooked you back then. Nice collection of Saitos and models.

donkey doctor

Hello; regarding pipe vs. corrugated flex pipe. My experience has been that there is no noticable performance difference. I have tried both on the 50, 56, and 80 singles and the 100 twin. One thing I did noticed was that the corrugated pipe fills it's corrugations with oil while the engine is running, so the tone changes as the pipe fills. On the 80, the flex pipe sounded better then the stock pipe, but the tach readings were identical.

The fles pipe will drain it's oil out slowly, or pour it into the exhaust port depending how you hang it.

1rcaddict

I'm replacing the bearings in my 82 and realized I don't have a gasket for the timing gear case, is it absolutely necessary or will a gasket sealant work?

w8ye

My Feedback: (16)

The gasket for the timing gear case is critical.

Due to the meshing of the timing gears

.007" - .012" is the nominal thickness

1rcaddict

Is there a material, obtainable locally, that is suitable to make one?

w8ye

My Feedback: (16)

Use a magazine cover or a post card or index card

Shack

Don't see me on the Club Saito list yet.

FA-72 [love it!]

Howard Shackleford
SC

1rcaddict

I'm replacing the bearings on a FA-82 and I read in an article to remove at least one of the shields on the rear bearing to allow for better lubrication, is this correct?

w8ye

My Feedback: (16)

I've taken a lot of Saito's apart and when it comes to rear shields, I've seen all combinations.

I consider it to be better to remove both rear shields but from looking at old engines it doesn't make much difference if they are both installed or just one or no shields.

Sealed bearings can be a different story

1rcaddict

So then you recommend removing at least one? Why do they come with shields if they are lubricated better without them?

w8ye

My Feedback: (16)

The shields are easily removed. It makes for lower inventory levels at the warehouse. The shielded bearings are more commonly used in industry.

1rcaddict

Thanks for the advice, i'll remove them.

blw

My Feedback: (3)

shack- you are #580

s10junky83

So what does it take to be accepted as a club member? I have just purchased a BEAUTIFUL Saito 100 and strapped it to the nose of a Hangar 9 Funtana s .40 !!!!