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I need help with a Saito 125. It's a new engine that I installed in a Great Planes Decathlon (Giant Scale 89" Wing Span) kit. The engine is installed inverted with a stock muffler but right angle (90 degrees) manifold. I use Powermaster 20/20 fuel and a 16x6 Zoar wood propeller. I have broken in the engine with about 1.5 gallons of fuel and it runs well with a good transition from low to high. My issue is that I can only get about 8600 RPM's at full throttle. I called Horizon and they told me that 9000 RPM's is the max I should achieve and that 8600 is the low end but not necessarily bad. I have find tuned the low end idle and that is running perfectly and I can tune the high end but only at a max of 8600 RPM's. Can anyone tell me what their experience is with these engines, especially maximum RPM's. Also, has anyone used a 17x6 propeller to improve the RPM's? thanks in advance for any assistance. Capt Lou
RC-Fanatic- okay, I see where you are coming from. The low speed should stay set once the engine is completely broken in and you get the needle set just right.
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I like the MA 14x8 three blade best on the 125. Maybe not for that particular plane. Favorite 2-blade is the 15", like blw says. I never found a 16x6 that ran well on the 125.
Last edited by mike early; 10-24-2014 at 08:19 AM.
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I need help with a Saito 125. It's a new engine that I installed in a Great Planes Decathlon (Giant Scale 89" Wing Span) kit. The engine is installed inverted with a stock muffler but right angle (90 degrees) manifold. I use Powermaster 20/20 fuel and a 16x6 Zoar wood propeller. I have broken in the engine with about 1.5 gallons of fuel and it runs well with a good transition from low to high. My issue is that I can only get about 8600 RPM's at full throttle. I called Horizon and they told me that 9000 RPM's is the max I should achieve and that 8600 is the low end but not necessarily bad. I have find tuned the low end idle and that is running perfectly and I can tune the high end but only at a max of 8600 RPM's. Can anyone tell me what their experience is with these engines, especially maximum RPM's. Also, has anyone used a 17x6 propeller to improve the RPM's? thanks in advance for any assistance. Capt Lou
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I need help with a Saito 125. It's a new engine that I installed in a Great Planes Decathlon (Giant Scale 89" Wing Span) kit. The engine is installed inverted with a stock muffler but right angle (90 degrees) manifold. I use Powermaster 20/20 fuel and a 16x6 Zoar wood propeller. I have broken in the engine with about 1.5 gallons of fuel and it runs well with a good transition from low to high. My issue is that I can only get about 8600 RPM's at full throttle. I called Horizon and they told me that 9000 RPM's is the max I should achieve and that 8600 is the low end but not necessarily bad. I have find tuned the low end idle and that is running perfectly and I can tune the high end but only at a max of 8600 RPM's. Can anyone tell me what their experience is with these engines, especially maximum RPM's. Also, has anyone used a 17x6 propeller to improve the RPM's? thanks in advance for any assistance. Capt Lou
G'day Mate,
I have a Saito FG21, which is the equivalent to a 125 Glow, but slightly less power, I run a APC17x6, on a Spacewalker, that plane loves the 17x6, I have tried a 16x6, and a 16x8, BUT on a Decathlon, which is designed for aerobatics, I would try more pitch, like a 16x8, or 16x10, this plane needs more speed.
The plane, & the way you fly it will determine the best prop, NOT RPM figures. By the sound of it, your 125 is not run in yet, & will develop more power as it runs in.
Fly it & forget theory, don't over think it.
Cheers
I have a Saito FG21, which is the equivalent to a 125 Glow, but slightly less power, I run a APC17x6, on a Spacewalker, that plane loves the 17x6, I have tried a 16x6, and a 16x8, BUT on a Decathlon, which is designed for aerobatics, I would try more pitch, like a 16x8, or 16x10, this plane needs more speed.
The plane, & the way you fly it will determine the best prop, NOT RPM figures. By the sound of it, your 125 is not run in yet, & will develop more power as it runs in.
Fly it & forget theory, don't over think it.
Cheers
For a scale flight speed and aerobatics with decathlons and similar a six pitch prop is ideal at the rpm we get from saito engines.On an 89" decathlon cap should be running a 150 or 180.
ps trev how's the 30 going?
ps trev how's the 30 going?
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Ok my stuff up the comment about more oil in fuel was directed at the guy who had overheating and poor idle with 15% oil mix.. O/heating can be put down to low oil, has happened often at my field likewise idleing. Last time I had this problem though was because of absolutely stuffed / rusted up bearings on my mates 65. I only use wooden props for the initial "run in" tank of fuel if ever the exception is my vintage XOAR props for WW1 models. They are great. Now the weather is great, the field 10 minutes away and a number of big models with even bigger Saitos to test and observe in operation. So enough of this as interesting as it is the wild blue yonder beckons
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Old Fart the old 30 is going great in my mates model (put grinding teeth sound track here). My new one is in the stand for run in cycle and the model (Lanzo Racer) is sitting lonely on the bench awaiting its transplant. Otherwise it is still virtually N.I.B.
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Capt Lou, I have a pair of 125's, one in Rare Bear and the other in a 1/5 scale WACO, (as they are side mount they have the appropriate Slimline mufflers to keep all but the exhaust tubes within the round cowls). Both are strong but I think the design lends more to lower speed torque than RPM. My only advice is to provide adequate mount damping as they can shake a lot of airframe if bolted to a metal or extremely rigid mount.
With a few Saitos in the fleet now my other comment would be that, to me at least, their prop specs always seem a bit on the aggressive side. I would not recommend working with the largest or highest pitch in the range, (and expect to see your higher RPM, as well). This is especially true if working with 3-blade props. On the 91 and 100 I find the best performance with a 13/8 three blade MA. This is at the very bottom of their range for the 91 and below that for the 100. For my scale type of flying those work best.
p.s. I also think you may not be completely worn in yet, even with a gallon and a half out the exhaust. Personally I lean towards that being a good thing. Any engine that peaks early makes me wonder how durable it will prove to be in service.
With a few Saitos in the fleet now my other comment would be that, to me at least, their prop specs always seem a bit on the aggressive side. I would not recommend working with the largest or highest pitch in the range, (and expect to see your higher RPM, as well). This is especially true if working with 3-blade props. On the 91 and 100 I find the best performance with a 13/8 three blade MA. This is at the very bottom of their range for the 91 and below that for the 100. For my scale type of flying those work best.
p.s. I also think you may not be completely worn in yet, even with a gallon and a half out the exhaust. Personally I lean towards that being a good thing. Any engine that peaks early makes me wonder how durable it will prove to be in service.
Last edited by Cougar429; 10-25-2014 at 06:28 PM.
Acdc i'm posting you a letter from france and a free castor oil scratch and sniff.Cap i hope you get a good average out of all the opinions so far.I don't like 125's they don't suit the flying i do,too big physically for the performance they have and my 115 will match it on the same prop.
Trev you are generous with your engines especially the thirty and grinding teeth is about right mate.What's that old aussie saying about never loaning your chainsaw or the handbrake out because ?
Trev you are generous with your engines especially the thirty and grinding teeth is about right mate.What's that old aussie saying about never loaning your chainsaw or the handbrake out because ?
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Acdc i'm posting you a letter from france and a free castor oil scratch and sniff.Cap i hope you get a good average out of all the opinions so far.I don't like 125's they don't suit the flying i do,too big physically for the performance they have and my 115 will match it on the same prop.
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This is the skinny from the break in of the 1.25 on Jan. 01 2006
I did the break in on the Saito 1.25 today, it took one hour and five minutes and consumed 32 oz of fuel. I started with the HS needle at 3.5 turns out from closed, the LS needle where it was shipped.
Prop--- Master Airscrew 16x6 Classic
Fuel--WildCat 10% Premium Extra
Plug--Stock, it looks like an OS-f
Temperature 40 degrees F
I did the usual 10 minutes at 4,000 rpm, actually 20, I went in the house to get the camera and the Missus wanted a sandwich. I then set the throttle at 5,000 for 20 minutes and then 6,500 for 20 minutes and took the high speed reading, I took the idle reading about 2 minutes before it ran out of fuel. There is a shaky spot about 3,200 rpm accompanied by smoke, the LS needle is 1.25 turns in from factory and can be leaned some more, the HS needle is at 2.375 turns out from closed for the High speed reading. It started on the first backflip and never offered to quit.
I did the break in on the Saito 1.25 today, it took one hour and five minutes and consumed 32 oz of fuel. I started with the HS needle at 3.5 turns out from closed, the LS needle where it was shipped.
Prop--- Master Airscrew 16x6 Classic
Fuel--WildCat 10% Premium Extra
Plug--Stock, it looks like an OS-f
Temperature 40 degrees F
I did the usual 10 minutes at 4,000 rpm, actually 20, I went in the house to get the camera and the Missus wanted a sandwich. I then set the throttle at 5,000 for 20 minutes and then 6,500 for 20 minutes and took the high speed reading, I took the idle reading about 2 minutes before it ran out of fuel. There is a shaky spot about 3,200 rpm accompanied by smoke, the LS needle is 1.25 turns in from factory and can be leaned some more, the HS needle is at 2.375 turns out from closed for the High speed reading. It started on the first backflip and never offered to quit.
Last edited by Hobbsy; 10-26-2014 at 01:02 PM.
Question on cooling. My FG-11 is running with the cowl on, this is the second flight since putting it on. About 10 minutes into the flight it stuttered at WOT, so I throttled back and continued to fly at half for a few more minutes, which it ran fine at, and a few more WOT tries it ran fine, but just to be safe I landed (my first perfect flare 3 point with teh T-Clips too), and as soon as the plane landed the engine quit. It quit the last time I flew it when landing too, but never before that.
I put it on the stand and ran it at WOT for a few minutes, then shut it down and put my thermometer on the head. It hit 180*F, and when I tried to start it, it wouldnt run well, so looks like it heat soaked. So does this sound like a cooling issue? I have the cowl baffled to direct air over the head, but I dont think I have enough exit space. I opened it up just a bit in the field behind the head, and flew again for about 15 more minutes, this time without issue. When I landed I took another reading and it was only 120*. Looks like it helped some, but not sure if this is the issue or not.
I put it on the stand and ran it at WOT for a few minutes, then shut it down and put my thermometer on the head. It hit 180*F, and when I tried to start it, it wouldnt run well, so looks like it heat soaked. So does this sound like a cooling issue? I have the cowl baffled to direct air over the head, but I dont think I have enough exit space. I opened it up just a bit in the field behind the head, and flew again for about 15 more minutes, this time without issue. When I landed I took another reading and it was only 120*. Looks like it helped some, but not sure if this is the issue or not.
Now lets get over this 'tractor factor' way you think about our very small engines pulling ever lighter arf airframes.I was 300 behind you with a mas classic 15x8@10% nitro,on 15% i'm 140 behind you on the same day and to me they both seem to give the same vertical performance on the same prop and airframes but the 115 accelerates quicker on that 15x8.
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Old Fart, chardonnay is a dry tastless thing, you assume to much, now Ceouchen Moselle, Traminer Reisling or if you want a lolly water drink Heiniken or Tiger (in original form not Aussie version) are ok but keep the ice blocks away please. I saw an e**l@#ic thing on the w/end pulling 16,000rpm plus, with a 16x6 up the front, interesting, also saw a 36 gas "start itself" (on board starter), and my mate total a Raiden (foamie glider) and a Saito 65 that "was only 3 years old" with a dud plug (the original one I might add) All a lot to dogest given the "problems" you guys are having with RPM's and props. Most common problem here is usually "over propping" and not matching prop to fuel to engine (not necessarily in that order) to get the desired outcome. You have to fiddle a bit here. A good and varied selection of props plus the ability to mix fuel helps. Consider Saito 65 in Texaco mode (fuel economy event) any where from 14x8, through 15x6 or 8 to 16x6 in prop size, usually APC, same engine same a/frame in duration with hotter fuel 11 to 12500rpm with a 12 x6 Bolly carbon prop.
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OK, the high compression .80 first run is in the books.
Saito .80 with 15.5 to 1 compression
Prop==13.5x6 Bolly with Tru Turn 3" spinner
C&H Ignition set at 31 btdc
Fuel==WildCat 10% 2/4
Exhaust==Davis SoundMaster in cowl muffler
Max rpm==10,290
Idle====1,582
Acceleration and top rpm are super smooth, the .80, the 1.00 and 1.50 all now have that trait. The picture is not very good, the sun was killin the camera.
Saito .80 with 15.5 to 1 compression
Prop==13.5x6 Bolly with Tru Turn 3" spinner
C&H Ignition set at 31 btdc
Fuel==WildCat 10% 2/4
Exhaust==Davis SoundMaster in cowl muffler
Max rpm==10,290
Idle====1,582
Acceleration and top rpm are super smooth, the .80, the 1.00 and 1.50 all now have that trait. The picture is not very good, the sun was killin the camera.
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I need help with a Saito 125. It's a new engine that I installed in a Great Planes Decathlon (Giant Scale 89" Wing Span) kit. The engine is installed inverted with a stock muffler but right angle (90 degrees) manifold. I use Powermaster 20/20 fuel and a 16x6 Zoar wood propeller. I have broken in the engine with about 1.5 gallons of fuel and it runs well with a good transition from low to high. My issue is that I can only get about 8600 RPM's at full throttle. I called Horizon and they told me that 9000 RPM's is the max I should achieve and that 8600 is the low end but not necessarily bad. I have find tuned the low end idle and that is running perfectly and I can tune the high end but only at a max of 8600 RPM's. Can anyone tell me what their experience is with these engines, especially maximum RPM's. Also, has anyone used a 17x6 propeller to improve the RPM's? thanks in advance for any assistance. Capt Lou
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Guys: Thanks again for all your suggestions. The final result is that I put an APC 16x6 and it turns about 9,000 RPM's. This will now be the solution for my 1.25. I also tried a Xoar 17x6 put it did not improve the situation, only turning about 8,000 RPM's. I hope this info helps someone else. Again, thank you all