wttiger42

I need some help guys. I built a Tiger 60 for my dad. I put my Saito 100 on it. The plane flys great but im only getting around 7-8 minutes of flying time out of a 12 oz tank around 1/2 to 3/4 throttle.

Isnt this too short? Im using 15% fuel and a 15x6 prop turning around 8800 rpm.

I read in another post that these motors create a lot of muffler pressure and tend to push the fuel into the motor and not get used. This seems to make sense to me because the bottom of the plane is covered in fuel that comes out of that breather nipple.

I dont think im running the motor too rich, its 2 turns out.

What do you guys think?

exeter_acres

My Feedback: (2)

how new is the motor?

they come from the factory SLOPPY rich on the low end needle.......
it really makes a difference

Hobbsy

My Feedback: (102)

Most likely the low speed needle is too rich, it controls 80+ percent of the throttle range. The # of turns is unimportant, 200 to 300 rpm rpm from peak is.

wttiger42

The motor was purchased new back in march. Its got a lot of flights on it. Im sure its good and broken in.

Im gonna try that low speed adjustment and see what happens.

Build-n-flyer-RCU

My Feedback: (4)

Turn that low end needle in! Usually it take a bunch of turns to get it right. The engine will not only use a lot less fuel, it will also run noticably smoother. Don't worry about hurting the engine, as long as you have a good idle and no deadsticks when doing spins then it is rich enough.

Walt

Jack Hyde

My Feedback: (1)

I fly a Saito .91 and use 4 ozs of fuel in a typical 8-10 min flight at mostly 1/2 or so throttle. I have run 2 gallons thru it and the low speed adjustment is leaned out.

rlmcnii

My Feedback: (3)

wttiger42,

I hesitate to enter this discussion. However, if you do not adjust the needles in a Saito carburetor properly, you will never get the engine to run correctly. If you have adjusted the HS needle and not touched the LS you should start over.

1. run the HS back out to the original setting, for a 1.00 it will be 4 or 5 turns open. Start the engine, and with the engine running at FULL-THROTTLE ONLY, lean the HS to peak rpm and leave it at that setting.

2. Now, start leaning the LS. You will probably have to go a long way with it. Lean it until you start to get a hesitation in the transition from idle to full throttle, or until the engine dies as you bring it up from idle. At that point, open the LS needle until you get a clean, reliable, transition. Open it 1/8 of a turn at a time while making this adjustment.
N.B.: As you lean the LS needle the idle speed will increase. Adjust the idle speed with the servo end-point-adjustment on the transmitter, or with the throttle linkage. Do not adjust the idle speed with the LS needle...it is a mixture control. Most posters seem to think that a reliable transition is more important than the lowest idle speed possible. In practice, I have found that they are absolutely correct.

3. Now , run the engine wide-open and readjust the HS so you are 300 (or so, some say more, some say less) rpms less than peak by richening the HS needle.

4. As you use the engine you may find that you have to touch up the settings a bit. Remember, adjust the HS ONLY with the engine at FULL-THROTTLE. Doing otherwise seems to be a fairly common error in setting up a Saito.

5. The LS needle, as has been previously stated, controls a Saito through most of its rpm range. It also controls fuel-burn and your happiness with the engine. The old hands say to expect a fuel-burn of 1oz./min/cu.in. at full-throttle. That would be 12 minutes at full-throttle for your Dad's set-up. At 50%-75% power settings he should be able to get 15 minutes with a nice reserve. Actually, you will be amazed at how little fuel a well-tuned Saito will burn. The 15 minutes will probably be very conservative.

A disclaimer: I am not a highly-experienced Saito operator. I made all the neophyte mistakes while setting up my first Saitos. Once the carburetors were adjusted properly AND in the proper sequence all was well.

Enjoy your 1.00

Hobbsy

My Feedback: (102)

One more thought, when leaning the LS needle, check the transition and high speed setting after every other change, the two needles effect each other and occasionally you need to re-do the HS needle after changing the LS one.

P-40 DRIVER

I use a very simple technique to tune my Saitos. After break in, set the top end at 300 rpm rich get the bottom end in the ball park with good transition with a bit of smoke when you open the throttle. Now fly the plane, if the engine dies during low throttle, such as power off spins, landing or taxing back to the pits after landing, its to lean, open the low end up one eighth of a turn and try again checking for 300 rich on the top end. If the motor does not die doing the above, Lean the low end one eighth and try again. At the point where it runs without stopping and is as lean as you can make it is where you want to set it. Always use a tach and allow the engine to stabilize after any adjustment so you get a true reading. Always do your adjustments on full tank for consistant readings. Fine adjustments are done one eighth and one click at a time. Properly setup, a Saito should almost never quit in the air or the ground. By the way, the best idle is achieved with heavy props. Switching from a wood a composite prop or to larger diam. prop wil make big difference.

rlmcnii

My Feedback: (3)

low@slow,

Your method for setting the LS needle is, in practice, how I set mine also. Lean it until it quits on transition (take-off , long final, long,idling down-line or whenever) and then open 1/8 of a turn at a time until it won't quit. Additionally I have found, in practice, that it is best to fly the plane for a few minutes before fine tuning the needles. They seem to warm up more evenly under a light load than just sitting and idling.

As you have noted; once properly tuned a Saito will almost never quit in the air. Not infrequently, it is necessary to blip the throttle a bit(at least for me) to determine that they are still running and....they always are.

Hobbsy

My Feedback: (102)

R, you can find that spot a safer way, when you get it about as lean as you dare just blip the throttle in small quick blips, if it hesitates it's too lean and if it handles them just fine it's spot on.

rlmcnii

My Feedback: (3)

H, thanks

Build-n-flyer-RCU

My Feedback: (4)

I agree with all of the above, especially the last several posts. This is the best thread I've seen on how to set the bottom end on a Saito and I hope that all of the "idle too rich" Saito owners out there take the time to read through it!

Walt

rlmcnii

My Feedback: (3)

Build-n-flyer-RCU,

While learning my way around Saitos I found that they will run well with the LS needle way too rich. Many new users seem to fly them without ever touching the LS needle. I have watched people set up two-strokes and never touch the LS needle as long as they will idle at all. Perhaps the reluctance to tune the LS needle on a Saito is a holdover from people's two-stroke experience. I'm not at all certain as to the reason, but it certainly seems to happen.

A little unhappily, Saitos are shipped new with the LS needles set very rich. However, they run much more efficiently, smoothly, and reliably when properly run in and set up.

Hopefully, Wttiger 42 and his dad will be able to get their 1.00 set up well and be able to appreciate how nicely these engines run.

There is a lot of good information from many people available here.

wttiger42

Thanks everyone for your input. Im going to try something this weekend and see what happens.

Hobbsy

My Feedback: (102)

I'm sure they are set rich by design because if they came set lean most would get fried or be very difficult to start on their first run, few would check how it was set before starting it.

P-40 DRIVER

I have found, in practice, that it is best to fly the plane for a few minutes before fine tuning the needles. They seem to warm up more evenly under a light load than just sitting and idling.

I do the same thing, let it get could and stable on the ground by running at full throttle for a minute or two.

P-40 DRIVER

Oh I screwed that up. Lets try that again. I do the same thing except on the ground at full throttle. I will figure this quote thing out one of these days. [:-]

Hobbsy

My Feedback: (102)

Don't bother learning the Quote thing, it doesn't make any sense to re-write some one elses. entire post a second, third or fourth time. It just wastes server capacity and slows the system.

Build-n-flyer-RCU

My Feedback: (4)

rlmcnii,

I agree that most new users do not adjust the low end because they find that the engine will run OK with the factory needle setting which are extremely rich. They just don't realize the effect this has on fuel consumption and smoothness of operation. I have adjusted many Saitos at my field for folks with these complaints and they are often nervous that leaning the idle too much will hurt the engine. But it is absolutely necessary to get a Saito to run smooth and make fuel consumption reasonable.

Walt

corkguykev

i agree about the low end setting on a saito 100. when my one was new it was drinking fuel and i thought it was the high end being new so i tuned the high end down too low and had no power. when i tuned the low end instead it was frightening how little fuel it was burning when set properly. one thing though, make sure to run saitos a little rich on high end. mine died of bearings and conrod wear after 50 flights because i was tuning her too lean for performance in competitions. i have since repaired it and its running rich from here on. its much easier and cheaper to put fuel in her rather than parts.

rc-sport

My Feedback: (12)

Use the pinch method to tune your low end, it's quick, easy, safe and reliable. Make sure you retune your highend after your lowend is dialed in.

NM2K

My Feedback: (14)

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My philosophy on server space is that they can always buy more. I need the quote in order to remember what I am responding too.


Ed Cregger

Hobbsy

My Feedback: (102)

Ed, you should not have that problem for 15 more years.

The pinch test responds too slowly on fourstrokes.

rc-sport

My Feedback: (12)

Not if you pinch the line right at the carb inlet. Besides when the needle is rich you'll be using fuel quickly.