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Saito FG-17 tuning question

Old 05-27-2012, 12:58 PM
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corvettez06
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Default Saito FG-17 tuning question

This is my first gas four stroke engine (actually first four stroke for that matter) and the instructions give a ground rpm range of 2000-9500. I am using a K series 14x6, high speed needle is out 1.25 turns per manual and it runs excellent except I am nearing 11000 rpm at full throttle. I only did this once because of the fear of over revving it.

Are the high speed needles onfour strokes, whether gas or glow, supposed to be adjusted not to exceed the rpm range (9500 in this case)? Or should they be adjusted similiar to a two stroke and back off a little after reaching max rpm?
Old 05-27-2012, 01:22 PM
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Default RE: Saito FG-17 tuning question

14 X 8 would be the correct prop
Old 05-27-2012, 02:06 PM
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corvettez06
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Default RE: Saito FG-17 tuning question

You are right, 14x8 is the minimum recommended prop, but I am sure with that prop I willstill be over the recommened rpm.
Old 05-27-2012, 02:43 PM
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Default RE: Saito FG-17 tuning question

Run a 15 X 6 then?
Old 05-29-2012, 07:23 PM
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MercerAUST
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Default RE: Saito FG-17 tuning question

You should run the engine in by setting the high speed needle (probably half to one turn out from optimal so it starts to stumble at mid-revs) so the engine cannot exceed about 4,000/5,000 rpm for about the first 30 minutes (5-10 minutes on, then off for 5-10 minutes and so on). Try to vary the throttle settings a little.

After this initial run in, you can start to lean it to optimal. The engine takes about 4 hours to run in before you can optimal tuning (eg don't worry about getting it perfect until you have run time). Just tune it on the plane so it is realiable and not likely to dead stick. In my view, you don't to run the engine in on the ground for hours. After the 30 minute initial ground tune you can start flying the engine, but keep off the full throttle (except for take-off and emergency). After a further hour run time, running continously at WOT should be OK. As w8ye says, the engine should be propped to run in the recommend range. Make sure you use the recommended Saito fuel/oil mix (20:1 with good synthetic oil) for at least the first 10 hours.
Old 04-11-2019, 01:19 PM
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Default FG 17 break in

Originally Posted by MercerAUST View Post
You should run the engine in by setting the high speed needle (probably half to one turn out from optimal so it starts to stumble at mid-revs) so the engine cannot exceed about 4,000/5,000 rpm for about the first 30 minutes (5-10 minutes on, then off for 5-10 minutes and so on). Try to vary the throttle settings a little.

After this initial run in, you can start to lean it to optimal. The engine takes about 4 hours to run in before you can optimal tuning (eg don't worry about getting it perfect until you have run time). Just tune it on the plane so it is realiable and not likely to dead stick. In my view, you don't to run the engine in on the ground for hours. After the 30 minute initial ground tune you can start flying the engine, but keep off the full throttle (except for take-off and emergency). After a further hour run time, running continously at WOT should be OK. As w8ye says, the engine should be propped to run in the recommend range. Make sure you use the recommended Saito fuel/oil mix (20:1 with good synthetic oil) for at least the first 10 hours.

I just ran my FG17 for the 30 min. break in, thanks for your post. It helped a great deal, as the book was not great.
Old 04-12-2019, 10:26 AM
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Originally Posted by corvettez06 View Post
This is my first gas four stroke engine (actually first four stroke for that matter) and the instructions give a ground rpm range of 2000-9500. I am using a K series 14x6, high speed needle is out 1.25 turns per manual and it runs excellent except I am nearing 11000 rpm at full throttle. I only did this once because of the fear of over revving it.

Are the high speed needles onfour strokes, whether gas or glow, supposed to be adjusted not to exceed the rpm range (9500 in this case)? Or should they be adjusted similiar to a two stroke and back off a little after reaching max rpm?
I've got the FG-21 and run the MAS K Series 16 x 6 and it pulls really nice. I can't remember the RPM at full throttle but I think it was around 9500 RPM or so. 11000 RPM seems really high for a 4 stroke, I'd use at least a 15 x 6 to avoid damage to the engine.

I love my Saito FG series though, what a great engine. Also want to mention that I run mine a little on the rich side also.
Old 04-14-2019, 12:09 PM
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Default max rpm

Originally Posted by corvettez06 View Post
This is my first gas four stroke engine (actually first four stroke for that matter) and the instructions give a ground rpm range of 2000-9500. I am using a K series 14x6, high speed needle is out 1.25 turns per manual and it runs excellent except I am nearing 11000 rpm at full throttle. I only did this once because of the fear of over revving it.

Are the high speed needles onfour strokes, whether gas or glow, supposed to be adjusted not to exceed the rpm range (9500 in this case)? Or should they be adjusted similiar to a two stroke and back off a little after reaching max rpm?
I have had Saito Glow for about 35 years and they all have a max RPM. They never gave ground RPM, so I always set the ground RPM about 800 RPM's under the max. Has to do with the 4 cycle and what all the little moving parts can take. Don't want to make them mad. LOL
I would stay under the max ground RPM and as the book says. Max power if between 8500 to 9300 on the round. no need to go over 93K.
Old 09-12-2019, 12:42 AM
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Angry I don't understand the manual of Saito FG 17

I'm Italian and I don't understand this part of the manual well:


On the FG-14C, FG-17 and FG-21 the low-speed needle should be set at 7-5/8 from closed. ???
1. Disconnect the throttle arm from the throttle pushrod.
2. Manually hold the throttle barrel closed.
3. With a small tip flat screwdriver, screw in the idle adjustment all the way until you feel the throttle barrel trying to rotate. ???
The low-speed adjustment is actually not a needle—it is a sleeve that cover/ uncovers a cat’s eye slit in the fuel supply tube. When you run the low-speed adjustment all the way in, the sleeve will bottom out against the fixed carb body and force the barrel to rotate. ???
4. Now richen the low-speed needle by 7 turns, 35 minutes. In our experience, this will be within an 1/8 of a turn (+/–) from perfect at the low end. ???
5. Reconnect the throttle pushrod.
6. Once this change is made to the low end, open the high end by 1/2 turn from where you ran it before, restart the engine and reset the high-end needle valve.
Please refer to the diagrams.
The minutes listed are in reference to the minute hand of a clock. FG-14C FG-17 FG-21 ???
High-speed needle 1 turn 20 minutes 1 turn 30 minutes 1 turn 30 minutes ???
Low-speed needle 7 turns 35 minutes 7 turns 35 minutes 7 turns 35 minutes ???

Must I turn Low-speed needle 7 turns ??? I don't understand.

Can anyone help me understand? Should I run Low-speed needle 7 times ???

Thanks a lot
Old 09-12-2019, 10:11 AM
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FP; turn the LS needle closed (clockwise) until it stops turning, the LS needle will be fully closed (leaned) at this point. Now open the LS needle by turning it counter clockwise (richen) 7 turns 35 minutes, which is 7 & 1/2 turns open (rich) + another 5 minutes open like in a clock's hand movement, the distance the clock hand moves to mark 5 minutes.

Roger
Old 09-13-2019, 12:10 AM
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Hi ForcesR,

Let's see if I have understood correctly. 7 turns of 35 minutes are 245 minutes. Divided by 60 minutes, they are about 4 turns of 360 degrees.

To open the-low needle speed of other 5 minutes, you need to turn CCW the screw 30 degrees (60 minutes are 360 ​​degrees, divided by 12 = 30 degrees).

Also you need to turn the high speed screw 1 turn CCW of 180 degrees plus 1 turn of 90 degrees (1 turn 1/2 per manual).

Is it right? In my country 1 turn = 360 degrees, not 180 degrees. Our system is easier.

Vittorio

Last edited by Fast Pilot; 09-13-2019 at 06:31 AM. Reason: another clarification
Old 09-13-2019, 09:42 AM
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Vittorio; 1 full turn here in North America is also 360 degrees. Turn the LS needle counter clockwise (richen) a full 7 & 1/2 turns open + another 5 minutes open. 5 minutes in a clock hand movement is approximately 8 degrees.
The HS needle from fully closed is turned counter clockwise open (richen) a full 1 & 1/2 turns.

LS needle turns 7 & 1/2 + 5 minutes open = 7 X 360 degrees + 1/2 turn = 180 degrees + 5 minutes = 8 degrees open.
HS needle turns 1 & 1/2 open = 1 X 360 degrees + 1/2 turn = 180 degrees open.

Roger

Last edited by ForcesR; 09-13-2019 at 10:23 AM.
Old 09-13-2019, 12:55 PM
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Smile I misunderstood

Thank you ForcesR.

I misunderstood because 7 and 1/2 turns seemed too much. Be careful though: 5 x 12 = 60 minutes (360 degrees). 360 divided by 12 = 30 degrees. 5 minutes are 30 degrees.

What battery would you recommend for the ignition system?

Thank you
Vittorio
Old 09-13-2019, 03:41 PM
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Vittorio, the ignition batteries I use on all my Saito gas engines is a LIFE 2S 6.6V 1800mah. I have an FG-20, 2 x FG-21's, FG36, FG60R3, and FG90R3. A 5-cell Ni-Cd or 5-cell Ni-MH is sufficient for your requirement too.

Roger

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