Saito 91 4s VS O.S. Surpass 91 4s

[statbeast]

I love the Saito .91 if you are buying used or if you already own one. If you are buying new then the 100 is a better buy given the fact that it is lighter and more powerful. Even if you don't need more power for the cub, the 100 will be a better fit for future planes and will have a better resale value if you want to sell later.

I would not buy an OS over the Saitos. The Saitos are just beatiful engines, light, reliable, powerful. It is true that the mufflers fall off which is annoying. I have learned the hard way that you need to get the engine hot and then crank that muffler nut as hard as you can. Once you get it right, it will stay on for years. But if it is at all loose, it will come off and deadstick you at the worst time!

[mark nichols]

Really late on this one but OS91 all the way, superb starter and runner what more do you need never missed a beat,and its also runs on hardly any fuel been on both a large cub and now in an ef extra 58" superb in both.

Im sure you would be happy with either so whichever balances the plane best.

Mark

[Craigsc5]

Before you buy consider the new Saito 115, I have not seen one yet but as I understand it the engine has a 91 lower end with a 125 top end. Maybe one of the guys will know about this engine.

[rv_ator]

I have an OS 91 Surpass and a Saito 100. I have had both engines on a 60 Ultra Stick. The Saito will spin a 15 x 6 APC on 20/20 powermaster the OS could only do about 8300 on the same prop. Both flew the plane great,the OS weights more but does use a lot less fuel and leaves less exhaust goo on the airframe. I flew the US60 with the OS for 33 gals of fuel. It was great combo. That motor went on a Katana profile and now the US has the Saito on it. If you need the weight on the nose and don't want to burn as much fuel the OS is great. If you need a lighter motor with a little more power the Saito is the choice. Both are absolutly realiable and are good quality engines.

[zoomer260]

Okay the thread has been around awhile and may be moot.

For the people that bring up how much fuel they burn I have this to say.

The more fuel you can burn the more POWER you have. The fact that two different makes the same displacemnt has one "guzzling" fuel that fact alone gives a great idea which makes more power.

Burning fuel is the reason combustion engines exist ! The more the better. If you don't really want or need that much power step down an engine size or keep your thumb out of it. Just like gas milage in a car. None will come close the the advertized milage if you run it WOT all the time.

Saito wins. Both cost too much these days, I wish I had never sold a single one that had.

[zoomer260]

	Quote: Originally Posted by rv_ator
	I have an OS 91 Surpass and a Saito 100. I have had both engines on a 60 Ultra Stick. The Saito will spin a 15 x 6 APC on 20/20 powermaster the OS could only do about 8300 on the same prop. Both flew the plane great,the OS weights more but does use a lot less fuel and leaves less exhaust goo on the airframe. I flew the US60 with the OS for 33 gals of fuel. It was great combo. That motor went on a Katana profile and now the US has the Saito on it. If you need the weight on the nose and don't want to burn as much fuel the OS is great. If you need a lighter motor with a little more power the Saito is the choice. Both are absolutly realiable and are good quality engines.

You neglected to say just what the Saito did on the prop ?

[mark nichols]

My OS uses hardly any fuel these days i fly gas mainly!!


Mark

[krayzc]

i am with u Mark

[bodofish]

I've owned several of both brands but it seams like I just keep going back Saito. It's hard to beat gold valve covers.

[god-of-engines]

I like the lighter weight of the Saito, hate the expensive head cost should the muffler span a piece of the threads out, like the lumpy sound of the Saito, find OS can tolerate 2 stroke fuel / lower nitro content for achieving a smooth idle, it's a toss up. OS runs a little lower in the resale market.

[mark nichols]

Id go for an OS anyday, having owned my91fs for about three years and having hammered it to death it still starts no bother and i abuse it when not flying far bigger plane using gas, starts like clockwork every time.

I dont do mines better than yours can only recommend what i have, but will say my DA starts a breeze but my zdz's are real stump pullers, oh and lite planes fly better but break easier.

Mark

[5150flyer]

I have a Saito 91 with about 3 gallons of fuel through it for sale. PM me and I will send you a picture.

Strong running engine.