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-   -   SAITO .72 AAC (http://www.rcuniverse.com/forum/questions-answers-154/11343243-saito-72-aac.html)

TPL33 12-24-2012 04:00 PM

SAITO .72 AAC
 
Received my SAITO .72 AAC the other day. While looking at it, I noticed that when mounted on the airplane (it'll be mounted on its side, with the valve covers toward the left looking from the front of the plane), that the High Speed Needle Valve will be at the bottom of the engine. I read somewhere that on SAITO engines (maybe not the .72 AAC), that you can turn the carburator/needele valve assembly 180 degrees. I read through the manual and didn't see any instructions for doing this. Is turning the carb/needle valve only an option on some engines?

fredscz 12-24-2012 05:11 PM

RE: SAITO .72 AAC
 
It is very easy to do. Use the proper fitting screwdriver to remove the two screws holding on the carb body. Gently pull the intake tube from the head with the carb and turn the carb 180 and reinstall. Takes longer to talk about it than to do it.
Be careful with the o-rings and don't damage them.
Fred

tailskid 12-25-2012 08:36 PM

RE: SAITO .72 AAC
 
TPL33, if you need any assistance, I'm only a couple of miles away....

Jerry

TPL33 12-25-2012 09:21 PM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: tailskid

TPL33, if you need any assistance, I'm only a couple of miles away....

Jerry
I may take you up on that! I'm back into the hobby after 23 years off, already flying a trainer well on my own. I always wanted a 4 Stroke back in the day, never got it though. Now that I can afford it, I bought one. Never messed with one though, so, I'm hesitant to turn the carb around, don't want to screw things up!

Old Fart 12-26-2012 02:01 AM

RE: SAITO .72 AAC
 
Well thats easy then,take freds advice

daveopam 12-26-2012 02:26 PM

RE: SAITO .72 AAC
 
I never pull the tube from the head. After you pull the screws. Just swivel the carb/tube to the side, spin the carb and then swivel it back in place. The way there is zero chance of not seating the O ring back in the head.

David

tailskid 12-26-2012 02:30 PM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: TPL33


Quote:

ORIGINAL: tailskid

TPL33, if you need any assistance, I'm only a couple of miles away....

Jerry
I may take you up on that! I'm back into the hobby after 23 years off, already flying a trainer well on my own. I always wanted a 4 Stroke back in the day, never got it though. Now that I can afford it, I bought one. Never messed with one though, so, I'm hesitant to turn the carb around, don't want to screw things up!
Where are you located? I'm near 99th Ave and Lower Buckeye Road....

Jerry

TPL33 12-26-2012 09:27 PM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: tailskid


Quote:

ORIGINAL: TPL33


Quote:

ORIGINAL: tailskid

TPL33, if you need any assistance, I'm only a couple of miles away....

Jerry
I may take you up on that! I'm back into the hobby after 23 years off, already flying a trainer well on my own. I always wanted a 4 Stroke back in the day, never got it though. Now that I can afford it, I bought one. Never messed with one though, so, I'm hesitant to turn the carb around, don't want to screw things up!
Where are you located? I'm near 99th Ave and Lower Buckeye Road....

Jerry
I'm in Avondale, Dysart Rd and Encanto, across from Estrella Mountain Community College....Tim

tailskid 12-26-2012 10:09 PM

RE: SAITO .72 AAC
 
I'm retired, so if / when you need me, just hollar........

TPL33 12-27-2012 09:46 AM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: tailskid

I'm retired, so if / when you need me, just hollar........
Thanks. Do you have 4 Stroke experience? I may need guidance on turning the carb (so the high speed needle is at the top) and maybe initial adjustment of the engine.

tailskid 12-27-2012 11:47 AM

RE: SAITO .72 AAC
 
No problem..I think I have 4 or 5 currently (all Saito's).....great engines.

TPL33 01-08-2013 09:47 PM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: daveopam

I never pull the tube from the head. After you pull the screws. Just swivel the carb/tube to the side, spin the carb and then swivel it back in place. The way there is zero chance of not seating the O ring back in the head.

David
You were correct. The person on here who said it takes less time to do it than talk about it was right. I got the carb turned tonight, piece of cake. Thanks for the inputs guys.

tailskid 01-08-2013 10:28 PM

RE: SAITO .72 AAC
 
TPL33, where do you fly?

TPL33 01-09-2013 09:16 AM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: tailskid

TPL33, where do you fly?

I'm a member of ARCS (Arizona Radio Control Society). The field is off Greenway Rd,as far as you can gowest on Greenway where itturns into a dirt road. How about you?

tailskid 01-09-2013 11:40 AM

RE: SAITO .72 AAC
 
I'm neat you :) I fly at CropDusters.....what a beautiful day it was today. GREAT bunch of guys to hang with.

TPL33 01-09-2013 08:33 PM

RE: SAITO .72 AAC
 

Quote:

ORIGINAL: tailskid

I'm neat you :) I fly at CropDusters.....what a beautiful day it was today. GREAT bunch of guys to hang with.
Wish I could have flown today....had to work! I usually fly 1-2 times a week, on Friday or Saturday. The weather has been great this winter, harly any wind!

tailskid 01-09-2013 08:35 PM

RE: SAITO .72 AAC
 
This Friday it appears it will be cold and windy, so I'm not flying and Saturday I'll be in Ontario CA for the AMA Convention. Bring your mittins if you go flying :)

TPL33 12-15-2013 10:06 PM

Jerry (tailskid)....I've been trying to send you a PM, have sent two, but I'm not showing any sent items in my profile. I need help setting up my Saito 72 engine, cannot get a reliable idle (low idle that stays running). Let me know if you can assist.

daveopam 12-16-2013 11:23 AM

I'll try to help. Most Saitos are set way rich from the factory on the low end. Turn it in 1/8 turn at a time until it stumbles when you quickly advance the throttle. It may help to leave the hot shot in place until you get close. When it stumbles as you advance power quickly it has gotten to the lean part of the low end. Fine tune it the thickness of the screwdriver blade until it is right. You will have to do this again when the high end is set after break in. Another factor may be the prop. If you use a light weight wooden prop the idle will suffer. I heavier prop like an APC will give a flywheel effect and be able to idle slower.

david

TPL33 12-16-2013 03:56 PM

Quote:

Originally Posted by daveopam (Post 11686284)
I'll try to help. Most Saitos are set way rich from the factory on the low end. Turn it in 1/8 turn at a time until it stumbles when you quickly advance the throttle. It may help to leave the hot shot in place until you get close. When it stumbles as you advance power quickly it has gotten to the lean part of the low end. Fine tune it the thickness of the screwdriver blade until it is right. You will have to do this again when the high end is set after break in. Another factor may be the prop. If you use a light weight wooden prop the idle will suffer. I heavier prop like an APC will give a flywheel effect and be able to idle slower.

david

Thanks. I have to get some help with this. I've been tweaking this thing for 3 sessions now and can't get it. Even with the high needle set to max rpm, then backed off 300 rpm, this engine is filthy, blubbering, slobbering rich. I started turning in the low speed needle, adjusting the trim, and it won't hold an idle below 3,100. This makes my plane self taxi on the ground at a ridiculous speed. I used a 13X6 Master Airscrew prop for break in, still using it. My only question now is should I go ahead with the valve adjustment seeing I have close to 2 hours on the engine or should I wait until I'm done getting the engine fine tuned? By the way, know that I've never been a good engine guy (usually need help) and this is my first 4 stroke ever! Needless to say, I'm frustrated!

daveopam 12-16-2013 04:47 PM

It can be frustrating. You will never get the high end right with the low end really rich. I hate to tell you to lean it a bunch at a time because I don't want you letting it idle at a lean mixture. But you would be safe going more than a 1/4 turn at a time. If you get it too lean it just wont start. Just start it see if it will transfer. If it does shut it down lean the low and repeat. Do this until it stumbles or wont start and you will be close. At this point set the high then fine tune the low if need be. Also, not to start a MA vc APC prop war but I never had a 72 that really liked the MA prop. A 13x6 APC is the benchmark prop for a 72. You should get one. Adjusting the valves at this point wont hurt but more than likely is not your issue. Since you said " never been a good engine guy" this is how I do mine.
Pull off both valve covers.Rotate the engine until one of the valves is completely open. Take note of the prop position. Now rotate the prop one complete revolution. (360 degrees not 180)This will put that valve lifter you just saw all the way open on the back side of the cam. Loosen the jam nut slightly and leave the wrench on the nut with the allen wrench in the set screw. (it helps to bend the last 1/4" of the feeler gauge about 30 degrees) Now slide the feeler gauge in between the rocker arm and the valve stem. It should go in there but drag a little. If it dosen't tighten the set screw with one hand while working the feeler gauge back and forth. When you get the right tension take note of the position of the allen wrench. Now tighten the jam nut making sure the allen wrench does not turn the set screw. Check your clearance again. Remember the feeler gauge is the widest the valve clearance should be. The valve gap actually gets more when the engine is warm. Not less like a car engine. So it's hard to get it too tight. Now start all over to do the other valve.

BTW, your Saito will spit some oil out of the over flow nipple even if it set perfect.

david


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