After several months of research, I have selected this plane as my second plane. It consistently gets good reviews and people seem to really love this plane.

I want to put a four stroke engine in it, but am not sure which one, since this will be my first experience with a four stroke engine. I have an OS 46 FX on my trainer that has worked out very well for me. The Saito engines appear to be high quality and very well liked. Does anyone know how well the Saito FA-91S will pull this plane? What will the vertical capability be? How much better would the FS-100 be with an additional 0.2 hp?

An alternative would be a Moki 61 that someone gave me for free when they got out of the hobby. It is still new in the box. I don't know anything about it and am looking forward to experiencing a four stroke.

Thanks,

Travis

Try a Saito 72. Lighter than the 91 or 100 and plenty of power for this plane. Your not going to be doing 3D with this plane so you don't need to really over power it. JMHO

I would totally disagree with the previous reply (though very kindly so). I have experienced two of these from the kit form, one stock and one with no dihedral and extra sized control surfaces. Both with Saito 91, 72 would be much to small. Vert is not unlimited by any means, but will hover for several secs. With the 91 in it, it is very much an aro-bat, but will also slow way down!

IMO, one of the best second planes you could ever have, and my experience with SIG ARF's (I've got two of them) is that they are second to none.

GBISAK,

I too respectufully disagree with you. My credentials, I currently own one 4*40 two 4*60's and two 4*120's. I have built many, some bone stock and some full mod into 3D machines. BUT---this is only his second plane, he needs to leave the dihedral in and the control surfaces and throws stock for now so why put in a motor that will suck much more fuel, be more power than he needs, swing a bigger prop which on a four star with the low main gear might mean more prop strikes on less than perfect landings and with the heavier engine up front he will have to add ballast to the tail to get his balance correct. Maybe for his next plane but I am sticking to my guns when I say I think a Saito 72 is right for him now. JMHO

I have the 4*60 ARF with a Saito FA91 on it.I have to agree with Jim.It's more power than the plane really needs.It is a great second plane,especially for a low wing trainer.My opinion,the 72 will be a better choice for now.I fly the crap out of mine and hardly ever go over 1/2 throttle.To get the true feel for this plane.I say go with the 72.Just my opinion.

Hank

I have a Saito 100 on mine and it flies great, but I had to add 3 ounces of weight to the nose. See my gallery.
Bill

Hey Bluemax3
The Saito 91 Is perfect for this plane!!

Doug

NO - THE 91!!! (jumping up and down with a red face)


Well, to continue the disagreement, though respectfully, I would point out that the Saito 72 is the engine of choice for 40 sized planes, ie my World Models P51, and even a Somethin' extra at our field, and puts out MUCH less power than the average 2stroke 60 that the 4*60 was designed for. Though it would fly it, it would be just flying. The second plane is meant to explore the world and another trainer is not the right plane.

Weight aside, and you'll still need a little nose weight with the 91 anyway, there's no such thing as too much power, that's what the throttle is for. As to prop hits, this plane lands so well, easier than any trainer I ever had, I really don't think it should be considered unless the pilot was very poor at landing. As a matter of fact, landing is my second favorite manuver with this plane, the first being the torque roll.

I have yet to see anyone say the actually have, or had, a 4*60 with a saito 72. I actully believe it would be trouble waiting to happen, but I have never seen one, so I don't know.

I have an OS .91fs in mine and I wouldn't want anything less.The plane is really my son's who is seven tears old,he flies and lands it perfectly,has never had a prop strike.I also think the .72 is not enough,JMO.
Mike
BTW,I didn't have to add any weight to get it to balance on the recomended cg,

OK -The votes are in - I humbly stand corrected - go for the 91 if that is your choice. Honestly, RC pilots are worse than drag racers, can never get enough HP bolted on :-)

well toease your mind i had a ys91ac on mine a loved the poop outta of it!! love those 5 foot roll outs and vert !!!! so go with the 91 you dont have to use the power but youll always have it

Hey Jim
Just curious, but what engines are you using on your two four star sixtys? And how do you like the four star 120 ?

Doug

Doug,

My slightly lightened stock 60 is running, you guessed it, a Saito 72 and at 6 3/4 lbs it does all I ask of a stock 4*. My heavily modified 60 is running a Saito 100 and and at 7 lbs has totally unlimited power. My 120's are both modified and they are my favorite 4*'s. One is equiped with a Saito 180 and scales at 9 1/2 lbs the other is equiped with a RCS 140 gasser and scales at 11 lbs. Both have totally unlimited power and are absolute blasts to fly.

Jim

How about this. I have a Saito 65 in mine with a 11x6 prop and it leaps off the ground after about a 15 foot roll. Will fly all day at half throttle. Have gone as long as 45 minutes nonstop with a 16 oz. tank. Now for the best part. If BlueMax3 wants to move up to a bigger engine the Saito 80 and 91 has the exact same mounting dimensions as the 65. The 72 is different,smaller, so it would mean changing out the engine mount and drilling new mount holes etc. Just start with the 65 and later if the situation asks for more engine just drop the 80 or 91 right into it. Jm2cents

I am building one now, and I have allocated a lovely YS 91 to it.

A friend at the field flies his with a Saito 100, and to be honest either would be a good choice, but I am of the bigger is better school of thought.

WHy a YS 91, if you have to ask then you don't have a YS 91, it is a great engine,

So there you go, a great plane + a great engine = lots of fun

All of the choices given in this thread would do the job, IMO

Steve

Wow, I'm shocked that the 65 flies this plane, but to each his own! I would love to see it, and fly it of course. I have often seen this, where experienced pilots differ greatly in their opinions. I'm guessing you fly the 4*60 like I do my 1/4 spacewalker. Some say this bird is underpowered with a 91 4s, but I love it. Very relaxing! But to me, a 4*60, or any 2nd plane would be for tearing up the sky. Of course I did rip the wing off my first trainer in a snap roll gone wild.

What would be really fun, and a true test, would be to get one 4* and fly it with all the choices presented here on the same day, same conditions.

I'm curious how much nose weight the 65 needed for balance?

Gordon

I just reviewed SIG's specs on the 4*60, and I see the 4s range is 65 to 90. guess I should not be surprised it flies fin on the Saito 65.

If I had to choose between the .91 Saito and the 1.00. The 100 weighs like one additional ounce and considerable power difference between the two. A guy at my field had a four star 60 with a Thundertiger 60 on his and it was pretty much unlimited vertical. The Saito 100 is an awesome engine though. Just a little thirsty on the break-in period.

If you check the plans it shows a Saito 65 in the plane. With as much lift as the standard wing has it takes very little engine to make it fly. Mine has 8 oz. added to it directly under the engine to make it balance. I also have a Thunder Tiger 91 FS on the same type of mount to fit in it. Dave Brown 120 FS I believe it is.The Thunder tiger 91 FS requires no weight up front to balance perfectly. I simply remove the 8 oz. ballast. So I can swap out if I want to 'tear up the sky". Both have a Dubro 4 cycle throttle kit on the mount so everything hooks right up. Gives me both options. I can lazily float around for a long time with the 65 getting really good fuel economy or let it go with the 91.

Well here goes one more opinion, since I just registered on this site you may have allready decided. My 4star 60 has a ThunderTiger .91. As noted, perfect balance and plenty of power. This engine runs great with a OS 4st plug and pressure.

I have the BTE Venture 60 (same basic plane, same designer) and the 91 or 100 will be a smart choice.

Reason?
The 4 Star won't be your last plane....Eventually you'll want a Chipmunk, or the H9 Mustang...or the Ultra Stick...all of these will be a perfect match with a 91 or 100.

I also have the 72 and although it will fly it, probrably very well, the engine choice will confine you to 40 size aircraft mostly.

So thinking ahead at least a plane or two (old chess habit) I would best reccomend the 91 or 100.

Good luck and keep us posted.

As I said earlier the Saito 65,80, 91 all have the same mounting dimensions, but I forgot to include the 100. Believe it is the same also. If a person is experienced enough to control the extra power then it's just a matter of how much $ to spend. If they are still learning I would suggest picking up a good used smaller engine then make the plunge later. Remember, the faster they fly the faster and easier they crash!!!! An important point to always remember.

Welcome aboard GGALE

(I don't have a 4* so Im staying out of this one.) Cheers

I have a Four Star 60 that I have used 2 four strokes on, a OS 91 and a Magnum 91. The four stroke and size engine are great. I used to run 14x6 props and have switched to 14x8 props, a little more speed which makes knife edge much better and allows flying at half throttle. I also move the CG way back. I added 2 oz of lead to the tail wheel. This really brought the plane to life and it still flys like a ***** cat, not bad habits. The plane will lomshavac (sp?) , flat spin, hang on the prop and just about anything you could ask of it. Best all around airplane.

OK, Having just read this whole thread, I ask: did I make a mistake in just buying an OS.61 FX 2-stroke for the new 4* 60 coming from Tower? My only experience with a 4-stroke is a SIG Rascal with a SAITO.72. The plane flies great!!! But the 4* 60 is really my first low-wing.

Can always but the .61 in something else!!!


Michael