Saito 100 idle problem
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My Saito 100 - now well run in -seems to have an idle problem.
Having peaked the top end [using a tachometer] and then turned back by about 300 revs, I then try to lean out the bottom end. At present the bottom end needle is about two and a half turns out from fully closed. I can lean it further than this and still have a smooth throttle transition. However, the problem is that the further I lean it, the higher the revs needed for a sustainable idle. Leaning the bottom end as much as reasonably possible in terms of a smooth transition means the idle has to be about 3,000 revs. if it is to be maintained for more than a few seconds. This is really a bit too fast.
All the literature I have read suggests that the low end needle is to be 'tweaked' to adjust, primarily, the throttle transition and not the idle revs level.
Am I doing this wrong? Any advice gratefully received - many thanks.
Having peaked the top end [using a tachometer] and then turned back by about 300 revs, I then try to lean out the bottom end. At present the bottom end needle is about two and a half turns out from fully closed. I can lean it further than this and still have a smooth throttle transition. However, the problem is that the further I lean it, the higher the revs needed for a sustainable idle. Leaning the bottom end as much as reasonably possible in terms of a smooth transition means the idle has to be about 3,000 revs. if it is to be maintained for more than a few seconds. This is really a bit too fast.
All the literature I have read suggests that the low end needle is to be 'tweaked' to adjust, primarily, the throttle transition and not the idle revs level.
Am I doing this wrong? Any advice gratefully received - many thanks.
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Try to lean the low-end up to the point of having a sustainable idle at about 2,200 rpms, namely richen it and forget the best possible lean adjustment as far as transition is concerned. Then check what has happened with your transition. If transition is rather ok start flying your model. If not you should experiment with one of the following:
- different prop
- different fuel
- finally change the carb
To give you an example my Saito 100 idles at 2,200 having a rather rich transition with the low-end fully closed!
Stelios
- different prop
- different fuel
- finally change the carb
To give you an example my Saito 100 idles at 2,200 having a rather rich transition with the low-end fully closed!
Stelios
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Runway:
You need to remember that when you start having to raise the idle while leaning the LS needle you have gone too far lean. Your aim is to get the idle stop turned out as far as you can - lowest idle speed - by adjusting the LS needle. Then, from that point check the transition to full throttle, adjusting the LS needle as needed for good response. Sometimes you have to go far enough on the LS needle that the idle stop has to be reset also.
And as Stelios said, keep checking the HS as you adjust the LS.
Stelios:
Does this mean you finally resolved your dispute with the French dealer where you bought your Saito engine? Tell us how it came out.
Bill.
You need to remember that when you start having to raise the idle while leaning the LS needle you have gone too far lean. Your aim is to get the idle stop turned out as far as you can - lowest idle speed - by adjusting the LS needle. Then, from that point check the transition to full throttle, adjusting the LS needle as needed for good response. Sometimes you have to go far enough on the LS needle that the idle stop has to be reset also.
And as Stelios said, keep checking the HS as you adjust the LS.
Stelios:
Does this mean you finally resolved your dispute with the French dealer where you bought your Saito engine? Tell us how it came out.
Bill.
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I am curious to know what kind of plane and prop. Many set the idle rpms as not to pull the plane around if you know what I mean. Case in point is the Saito 100 on my .40 size P-51 with a 12/12 apc. That darn thing is barely running and I have to hang on to it. I know its all the set up but thats what I have to deal with.
ORIGINAL: Runway
My Saito 100 - now well run in -seems to have an idle problem.
Having peaked the top end [using a tachometer] and then turned back by about 300 revs, I then try to lean out the bottom end. At present the bottom end needle is about two and a half turns out from fully closed. I can lean it further than this and still have a smooth throttle transition. However, the problem is that the further I lean it, the higher the revs needed for a sustainable idle. Leaning the bottom end as much as reasonably possible in terms of a smooth transition means the idle has to be about 3,000 revs. if it is to be maintained for more than a few seconds. This is really a bit too fast.
All the literature I have read suggests that the low end needle is to be 'tweaked' to adjust, primarily, the throttle transition and not the idle revs level.
Am I doing this wrong? Any advice gratefully received - many thanks.
My Saito 100 - now well run in -seems to have an idle problem.
Having peaked the top end [using a tachometer] and then turned back by about 300 revs, I then try to lean out the bottom end. At present the bottom end needle is about two and a half turns out from fully closed. I can lean it further than this and still have a smooth throttle transition. However, the problem is that the further I lean it, the higher the revs needed for a sustainable idle. Leaning the bottom end as much as reasonably possible in terms of a smooth transition means the idle has to be about 3,000 revs. if it is to be maintained for more than a few seconds. This is really a bit too fast.
All the literature I have read suggests that the low end needle is to be 'tweaked' to adjust, primarily, the throttle transition and not the idle revs level.
Am I doing this wrong? Any advice gratefully received - many thanks.
#8

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try this web site, much information about Saito's and their carb adjustments.
http://saito-engines.info/throttle_setup.html
http://saito-engines.info/throttle_setup.html
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i HAVE HAD IT ALMOST 2 YEARS NOW. IT WAS MY FIRST 4 STROKE AND i PAY CLOSE ATTENTION TO THOSE HIGH RPMS ON IT. oF COURSE WHAT I LOOSE ON THIS i MAKE UP FOR ON ALL MY 2 STROKES

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Cyclic Hardover - re your question:-
I'm running the Saito 100 in a Hangar 9 Ultrastick 60 - 14x7 prop [APC] - 10% nitro fuel [nitro is much more expensive in the UK than in the USA].
Runway
I'm running the Saito 100 in a Hangar 9 Ultrastick 60 - 14x7 prop [APC] - 10% nitro fuel [nitro is much more expensive in the UK than in the USA].
Runway
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I adjusted my Saito 100 in the same manner as I did my two strokes and it has worked out fine using the sounds of the rpms to nail it down. While the engine is at an idle , I remove or pinch off the fuel line and let the engine quit.
If the rpms increase as the engine quits, the low end is to rich. if the rpms just go down and the engine quits--too lean. Every time you reset that low end adjusment, check the highend, then go back to re adjust the low if necessary.
One other thing is if this is your first fourstroke, they take some getting use to as far as sound , idle and the whole thing. Just the sound of them was giving me concern for a couple months. Sounded like the engine was not runing well when it was.
Most of the 4 strokes I see idling don't have that smooth sound as a 2 stroke and sometimes seems kind of rough like its on the verge of quitting
If the rpms increase as the engine quits, the low end is to rich. if the rpms just go down and the engine quits--too lean. Every time you reset that low end adjusment, check the highend, then go back to re adjust the low if necessary.
One other thing is if this is your first fourstroke, they take some getting use to as far as sound , idle and the whole thing. Just the sound of them was giving me concern for a couple months. Sounded like the engine was not runing well when it was.
Most of the 4 strokes I see idling don't have that smooth sound as a 2 stroke and sometimes seems kind of rough like its on the verge of quitting
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To Bill:
Yes, the French company returned my Saito-100 at no expense (not even the mailing cost) after the owner of a Greek R/C forum contacted him.
I had told my story to local r/c forums as I did in RCU. It seems that we (consumers) are gaining power through forums.
Stelios
Yes, the French company returned my Saito-100 at no expense (not even the mailing cost) after the owner of a Greek R/C forum contacted him.
I had told my story to local r/c forums as I did in RCU. It seems that we (consumers) are gaining power through forums.
Stelios