Saito ID and help
04-02-2005, 11:27 PM
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Saito ID and help
I while back I bought a used plane out of a consignment that has a Saito 65 on it. The engine seems to be old but in great condition and fires up easily. The high end is easy to set but the low end is a mystery. The other club members that have helped me with it are not familiar with the carb on it. It appears to have an air-bleed low end adjustment that I can't find any information on for this particular engine, the only 65 documents I have seen show a low-end adjustment via a screw inside the end of the throttle arm.
Could someone verify this from the attached pictures taken either side of the carb and give me some advice on setting the low end. I think I have it set but after flying for a few minutes if I try a touch and go I invariably get a dead stick..
Could someone verify this from the attached pictures taken either side of the carb and give me some advice on setting the low end. I think I have it set but after flying for a few minutes if I try a touch and go I invariably get a dead stick..
04-03-2005, 12:36 AM
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RE: Saito ID and help
Adam:
After bringing your pictures into Pain Shop and working with them a bit, I could see what you have. I've reposted the pictures here, and a crop of one with a red arrow added.
You do have an early FA-65 with the air bleed carb.
There were three problems with the A/B carbs on the 65s, two were easily corrected, the third was not.
First, was just plain maladjustment. The second was the throttle linkage, and the third was lack of a mid range adjustment.
We'll discuss the throttle linkage first, as it's the easiest to correct. Look at the red arrow in the third picture. This is a spring to hold the throttle barrel tight into the carb body, (A second end is there but can't be seen) and if the barrel is pulled out it will open the flow control valve on the inside end; it depends on the barrel being tight to work. If the throttle linkage tends to pull the barrel off its seat the engine will go rich. Check your linkage, if it has any side loading on the throttle lever be sure the barrel is pushed in, rather than pulled out.
This carb does not adjust the way a conventional two needle carb is done. Peak the high speed, then richen it for a 200-300 rpm drop from peak, and leave it alone. Take the engine down to idle, adjust the air bleed for best transition, not for best idle.Generally the idle will be good, but it's better to keep it running than to have a smooth idle with the engine cutting off in flight.
The mid range adjustment has to be done by fuel selection. The larger Saito engines with A/B carbs did have a mid range adjustment, they weren't so critical. My experience is good with 15% nitro in the old 65, but if your mid range seems rich try going up as far as 25% nitro. Or if it seems lean, try going down to 5% in the fuel. Wouldn't hurt to try a tank of both, see which way you want to go. Do reset the high speed when you switch fuels.
Hope this helps.
Fourth picture is an FA-120 A/B carb showing the mid range adjustment disc.
Bill.
After bringing your pictures into Pain Shop and working with them a bit, I could see what you have. I've reposted the pictures here, and a crop of one with a red arrow added.
You do have an early FA-65 with the air bleed carb.
There were three problems with the A/B carbs on the 65s, two were easily corrected, the third was not.
First, was just plain maladjustment. The second was the throttle linkage, and the third was lack of a mid range adjustment.
We'll discuss the throttle linkage first, as it's the easiest to correct. Look at the red arrow in the third picture. This is a spring to hold the throttle barrel tight into the carb body, (A second end is there but can't be seen) and if the barrel is pulled out it will open the flow control valve on the inside end; it depends on the barrel being tight to work. If the throttle linkage tends to pull the barrel off its seat the engine will go rich. Check your linkage, if it has any side loading on the throttle lever be sure the barrel is pushed in, rather than pulled out.
This carb does not adjust the way a conventional two needle carb is done. Peak the high speed, then richen it for a 200-300 rpm drop from peak, and leave it alone. Take the engine down to idle, adjust the air bleed for best transition, not for best idle.Generally the idle will be good, but it's better to keep it running than to have a smooth idle with the engine cutting off in flight.
The mid range adjustment has to be done by fuel selection. The larger Saito engines with A/B carbs did have a mid range adjustment, they weren't so critical. My experience is good with 15% nitro in the old 65, but if your mid range seems rich try going up as far as 25% nitro. Or if it seems lean, try going down to 5% in the fuel. Wouldn't hurt to try a tank of both, see which way you want to go. Do reset the high speed when you switch fuels.
Hope this helps.
Fourth picture is an FA-120 A/B carb showing the mid range adjustment disc.
Bill.
04-03-2005, 02:52 AM
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RE: Saito ID and help
It is really impressive how many things Bill knows about Saitos.
However, from my experience with engines in general and Saitos in particular, I would buy a new engine instead of trying to fix this old one.
Don't think too much about the engine cost because a few more deadsticks could lead you take an airplane cost as well or exit the hobby frustrated.
Stelios
However, from my experience with engines in general and Saitos in particular, I would buy a new engine instead of trying to fix this old one.
Don't think too much about the engine cost because a few more deadsticks could lead you take an airplane cost as well or exit the hobby frustrated.
Stelios
04-03-2005, 08:36 AM
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RE: Saito ID and help
Thanks for all the replies. I think I am going to tinker some more on it and the comment about the nitro is interesting. I have done the majority of flying/tinkerring using PowerMaster Saito 20/20 fuel (my first 4-stroke), one trip to the field I took along some 15% nitro fuel by mistake but flew with it anyway and I had the impression the engine was running better with it.
I was also wandering about replacing the carb and how much they are and I think that would maybe the next step since the engine really seems to be very serviceable even though it appears to be old and dirty (it does leak quite a bit of oil but I have been told this is pretty normal - is it?).
Cheers,
Adam
I was also wandering about replacing the carb and how much they are and I think that would maybe the next step since the engine really seems to be very serviceable even though it appears to be old and dirty (it does leak quite a bit of oil but I have been told this is pretty normal - is it?).
Cheers,
Adam
04-03-2005, 01:04 PM
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RE: Saito ID and help
Adam:
A new carb is certainly one way to go, but the engine ccan be made to run very well for $51 less.
And don't worry about the oil, be sure the vent nipple is not clogged and run a hose from it to the bottom of the plane.
Bill.
A new carb is certainly one way to go, but the engine ccan be made to run very well for $51 less.
And don't worry about the oil, be sure the vent nipple is not clogged and run a hose from it to the bottom of the plane.
Bill.
