_shadow_

Guys,

I am about to purchase the Saito 100, please let me know what props are yall runing and what RPM do you get?

This engine is for the Ultra Stick 60.

Thanks in advance to all who reply.

Regards
Marcus

Hobbsy

My Feedback: (102)

14x7 three blade, 9,500 rpm

mfuess

I have an identical engine/airplane set-up and found that a 14x8 (2 blade) works best. I have used a 14x7 three blade and it works well, but the mass weight slows the transition (throttle responce). Also, 20/20 fuel will give you superb idle and fast transition. I am very pleased with my Saito 100...

mfuess

DonM

15 - 6, 9800 ( my choice for my application, GP Spacewalker )

14 - 8, 8900

Cool Power 15% fuel, set 300 rpm's rich.

I found this engine veeeeery thristy, I had to install a 20 oz. tank to safely get 12 mins. As a matter of fact this engine has made me take another look at gas engines, maybe a RCS 140.

ilikeplanes

I think I may be off Saito because of the thirsty aspect. Too bad because they run great and look good. Other motors produce like power for far less fuel. My Saito 72 has an appetite similar to my Webra 1.20 two stroke. And, the Webra pulls an 11lb airplane quite respectably.

My $.02

Sport_Pilot

U'mm anybody run these things on a 14-6?

Hobbsy

My Feedback: (102)

I suspect it would float the valves with a 14x6.

Sport_Pilot

I doub't it. Most 4-Strokes are good to almost 14,000 RPM nowdays. Thats about 12,000 on the ground. I have run a TT 91 to over 11,000 with a 12-9 or 10 prop. Sure it was running over 12,000 in the air. No problems. Just wanting to compare. I suspect the TT 91 does better on small props, and the Saito 1.00 on larger props.

ilikeplanes

Sport_Pilot , I suspect you're right. I've always wondered why an itty bitty model engine has such a low advertised speed limit compared to it's size. My motorcycle has a red line of 10.5k and it has 325cc jugs. The piston speed of a 10cc engine running at 10k has about the same piston speed as my motorcycle at 3k. Valve speed must be similar too. That's not even cruising speed.

So what gives?

Sport_Pilot

I happen to know that some modlers have raced 4-strokes using the WM Midget Mustang. I think those who were winning were exceeding 12,000 RPM on the ground with an OS surpass. Running props such as 11-12 or something like that. This was posted on the usenet by a Mr. McDonald? He used to own a web based hobby supplier, sold a kit called a Balistick.

mfuess

For the benefit of "new" comers to FOUR STROKE engines, I highly recommend you keep the RPM within the Mfg's specification. Most four strokes can, and will turn higher RPM under the right circumstances. However you risk damaging your engine. IF you have the need for brutal speed, then hang a two stroke on your plane using the 2X formula. EI: If you plane calls for a 45 two stroke, then... 2x45=90. Therefore you would hang a 90 or 91 two stroke and prop it to your flying style. Please understand that this formula is radical and should not be employed by novice or intermediate builders/pilots.

DonM

Let's discuss this thirsty aspect about Saito engines, has anyone got an opinion why ?? My .56 and especially my 1.00 use huge quanities ( IMOP ) of fuel. I had an OS 1.08 2-stroke, I flew for years and always got 10-12 mins. with a 14 oz. tank My Saito 1.00 was running dry at 8 mins. with the same tank, had to install a 20 oz. tank. 15% fuel here in Canada is $30.00 with tax ouch !!!
I'm considering yanking the Saito and putting in a RCS 1.40. I can pay for it in about 300 flights.

Sport_Pilot

Most 4-stroke engines have a maximum recommended ground RPM of 11,000 to 13,000 RPM. Note OS engines vary by that much. http://www.osengines.com/engines/surpass.html

Unless you go into an extended dive at full power you shouldn't have any valve float problems if you keep static RPM below these numbers. Saito doesn't seem to have this spec listed on their site. Valve float doesn't automatically mean damage to the engine, though a cracked valve spring is possible. IMO the damage isn't expensive enough to unduly worry about it.

As for as drinking fuel. More power = more fuel. The TT. 91 eats up more fuel than any non supercharged .91, and it has more power. But service is terrible! Next time I will go with another brand. The first four strokes were low on power, used less fuel, and limited to 10,000 RPM (sometimes less, I think the first OS was limited to 9,000 RPM).

mfuess

Mr. DonM,

You have a serious problem if you are only getting 8 minutes on 14oz. tank!!!!! My Saito 100 running on 20/25 nitro, runs at .75 oz. per minute (at full throttle)! Yours appears to get 1.75 oz. per minute.... You're burning OVER DOUBLE what you should be!!

Mfuess

DonM

My .56 uses that much fuel. I have it in a FF Ultimate and if I run the whole flight at full throttle it will run a 6 oz. tank dry in 7 or 8 mins. You have to be flying a lot at 1/2 throttle or so to get that kind of mileage.

Sport_Pilot

While 1.75 oz./min seems high .75 seem almost equally low. My TT .91 gets less than 14 minutes on 25% nitro. I estimate about 12 minutes. I timed it at about 16 minutes running slightly rich on 10 or 15% nitro after installing it in the plane. After that I set my timer for 14 minutes figuring I would have enough part throttle time to be plenty safe. Well after switching to 25% nitro I didn't think to reset the timer. After several flights I had a deadstick. After setting the plane on the bench the timer went off. Opps I was out of fuel.

Aerosplat

My Feedback: (12)

I agree with mfuess,
You are burning way too much fuel in your Saito 100.
I have about 10 months on my Saito 100 now. I fly almost exclusively 3-D type stuff. I use an APC 15x4W, Cool Power 15%, and OS "F" plug, and Cline regulator (tank on CG). I get 10,500 RPM peak on the bench, and back off to 10,300 for flying. I have checked the engine at Wide open throttle on the bench and I burn exactly 9/10 ounce per minute (at 10,300 rpm). For 3-D stuff I use a 12 oz tank and fly for 10 minutes and always have ample fuel left after landing.
The ONLY way to adjust high speed needle with a 4 stroke is to use a Tachometer. Lean to peak RPM, then back off 200 RPM rich. On my Saito this is usually only 1 or 2 clicks on the high speed needle. If you are backing off 1/8 - 1/4 turn rich, you are running way too rich, and consumption will increase drastically.

Also note: I use a Futaba 8US transmitter. I have my timer slaved to the throttle channel. The timer does not run when the throttle is below 1/4. When I say I fly 10 minutes I mean by the timer, so my actual air time is closer to 12 - 14 minutes.

Sport_Pilot

Another post I made reminded me of something. At some point after switching to 25% nitro I switched to a colder plug, a K&B 4C to be exact. With this plug the engine was running obviously rich and leaning it out got me an additional 400 RPM. Not sure but I think this was after the dead stick. If you are running a high alloy hot plug like the OS-F, it will compensate somewhat for high nitro fuel but only when the mixture is rich which quenches the plug. Switching to a colder plug will allow a leaner mixture. The engine ran as good at idle after leaning out the low end also. But it would not idle as reliably with 15% fuel, it needed an OS-F or Fox Miracle plug for that.

Blackie

I'm running the Saito 100 on my Edge 540 T by AW with a 15X6 prop at I believe 9.2 rpm with Power Master 20/20. As far as fuel consumption goes I'm surprised to hear several of you are getting high fuel consumption. I have but only a 16 oz tank on mine and will stay in the air a good 17 min + of course I only fly at around 10 to 12 min time limits but once I'm done I still have over a half tank of fuel left.

I do know that until your engine is good and broke in you will see a high fuel consumption also make sure your engine is tuned good. If your valves are out of adjustment that may cause a high consumption in fuel.

Randy

DonM

I don't know, maybe I'm running too rich, but I'm getting over 10,000 peak with an APC 15 - 6 and back off to about 9800 which seems as good or better than anyone else, so it can't be too rich. I do know that I get a tremedous amount of oil & fuel out of the vent pipe and was playing with the idea of running it into the intake manifold between carb & engine, I believe the OS .70 has something like this, has anyone tried it ??

I've been running my .56 for 5 years now and it always uses about 6 oz. of fuel in 7 or 8 mins. which I also consider high. Oh I can lean them out and improve on my consumption, but they just sound too lean and I'm afraid of burning them up, something I have never done in 20 years.

These are the only 4-stroke motors I have ever owned and I really like them, very easy to start, never quit, idle great, 150 flights on a plug, sound great but they just seem to burn too much fuel. I was working my way up to larger 4-strokes but I think I'll stop right here.

Thanks for the help though ......................

lnorris

My Feedback: (1)

.

Blackie

I wonder if sea level might be playing a part in this?

Randy

Sport_Pilot

Just re-read my post. I forgot to mention that I was using a 14 oz. tank.

Sport_Pilot

Or maybe the lattitude, cool air is dense air is more air, which has to be matched with more fuel.

lnorris

My Feedback: (1)

.