Saito 91 keeps dying in flight?
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Saito 91 keeps dying in flight?
This is my first and only 4-stroke. The motor runs fine usually but sometimes stops without warning. Are there any previous threads that deal with this or do you have any ideas? I live at sea level.
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RE: Saito 91 keeps dying in flight?
That's not much to go on. When does it die? In level flight? Top of a loop? Verticl? Have you done the pinch test? Is your Saito new?
You might get a better result by posting in the Engines forum.
Jim C
You might get a better result by posting in the Engines forum.
Jim C
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RE: Saito 91 keeps dying in flight?
Level flight, half throttle, or on take off, or doing 3D, basically no pattern to problem. The motor is well broke in. Haven't heard of the pinch test. I do plan to extend the needle valve adjuster out so I can reach it better and try fine tuning some more.
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RE: Saito 91 keeps dying in flight?
Hey stdun...the pinch test will allow you to "fine tune" your needle settings. You could start by running the engine wot. Set the needle for a good rich "close" to max setting. Now then while engine is at wot, just give the fuel line leading from the tank to the carb a little pinch. Firm and quick and then let go. Listen to the engine...does it increase dramatically in rpm? If so you are probably still too rich, but not always. It will depend on the engine. If you pinch the line and it does not increase in rpm, it is too lean. If you get a slight increase in rpm when you pinch, you are there. Now you can work on the low speed needle. Adjust the low speed setting until you have a steady idle, and good...instantaneous throttle response. That's the pinch test. Try it and you'll get your settings pretty darn close to the optimum mixture. Works on four and two strokes too.
Jim C
Jim C
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RE: Saito 91 keeps dying in flight?
ST: be careful in using third-party muffler gadgets as some are restrictive. Last week, a modeler was having a heck of a time with his plane going deadstick. The carb seemed to be very sensitive on the high-needle end. After about 2 hours, one of the local members in frustration pulled of the muffler diverter, you know the little rubber or silicone dohicky that diverts oil from plane, and the engine behaved flawlessly.
Good Luck,
RevGQ
Good Luck,
RevGQ
#7
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RE: Saito 91 keeps dying in flight?
Sounds like the pick-up tubing inside the tank may have come off the brass outlet tube. Will run OK until the brass tube sucks some air - just a guess. Also the pick-up line may be kinked in a forward position in the tank.
Good landings.
Ray
Good landings.
Ray
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RE: Saito 91 keeps dying in flight?
Another good test is an old controliners test.
To check for leanness, with engine at full out hold the nose vertical if it falters and cuts its too lean! Richen it out, the carb will leanout somemore so a click or two extra are always good.
To check for leanness, with engine at full out hold the nose vertical if it falters and cuts its too lean! Richen it out, the carb will leanout somemore so a click or two extra are always good.
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RE: Saito 91 keeps dying in flight?
ORIGINAL: tetherite
Sounds like the pick-up tubing inside the tank may have come off the brass outlet tube. Will run OK until the brass tube sucks some air - just a guess. Also the pick-up line may be kinked in a forward position in the tank.
Good landings.
Ray
Sounds like the pick-up tubing inside the tank may have come off the brass outlet tube. Will run OK until the brass tube sucks some air - just a guess. Also the pick-up line may be kinked in a forward position in the tank.
Good landings.
Ray
HTH,
~Todd