dingo9882

I was just reading about how the Sig 4 Star 40 can take up to a .40-.59 4 stroke engine. But, I was just talking to somebody that told me that I can probably fit a .70 surpass in there. Does anybody know what I can put in there? What is the biggest engine I can put in and does anybody have any recommendations.

flyierjon

Yes a .70 surpass will fit fine. i had a 4 star with that engine and it flew great! alot quicker than normal thou...

bubbagates

My Feedback: (32)

Agreed, a 70 Surpass will fit but it will be way overpowered. Not that there is anything wrong with that as long as you use good throttle management

DOOM!

My friend has this plane with a O.S. .46 FXI engine, I will let him know the good news about the plane being able to handle a .70 surpass.

w8ye

My Feedback: (16)

The Four Star series of planes will fly well with a broad range of engines.

A Saito 72 or 82 might be a better choice for a big engine because they weigh less. The OS 70 is an excellent engine though.

Enjoy,

Jim

CGRetired

My Feedback: (1)

Mine has an OS50SX on board and flys just great. I upgraded it from an OS46FXi. Great plane.

Wonder

My Feedback: (7)

Dingo, what engine did you decide to go with and how does it work for you? I just bought another 4*40 kit to build this winter. The first one I built several years ago with a 46LA as a low wing trainer. This one I want to put a larger 4 stroke on. I can't decide if I want the Saito 56 or the Saito 72.

ChuckW

It should fit fine. You'll have to work a little harder on the throttle than on a smaller 2-stroke and you may have to work at getting the CG right but neither is a huge problem. I have the OS .70 4-stroke in my Hanger-9 Twist. It idles nice and has plenty of power.

dingo9882

either one of those sounds good. And they are both really light as well. I Put the FL-70 in mine and It was not that good, has a lot more torque then any 2 stroke I could have put in. Try the Saito's, I am not to familiar with them though.

WMB

My Feedback: (1)

I thought the FL70 would be good due to it's light weight. Mine currently weighs 4.5 lbs with a Saito 45. Did about 30 minutes of touch and goes last night, that was a kick. I have had a TT46 and ST51 in it also. The 51 was mucho fun, I think the Saito 72 would be even better. Be sure to get the CG toward the rear of recommended area to get the most out of it.
Have fun, MikeB

dingo9882

The FL-70 is very light. But it is not a very good engine. I flew a pattern contest with it and it made me look like a fool doing stall turns and loops. O.S. makes great engines, and this is the first one they made that I am not very satisfied with.

Wonder

My Feedback: (7)

The plans call for an 8 oz. fuel tank. Is that big enough for the .72 engine or does someone make a bigger tank that will fit in that hole?

Rcpilot

My Feedback: (78)

I had an OS 61FX in mine. I modified all the control surfaces by increasing them in size by 50%. It was my "poor mans" 3D plane way back when. It flew nicely and would hover.

I'd use a larger thank than 8oz for the .72 You can measure the tank you have and then try to find one from Tower that might be just a bit longer or maybe just a bit taller. It doesn't take much larger tank to get 2more ounces of fuel. 10oz should fly it for a long time if your not full throttle all the time.

Wonder

My Feedback: (7)

I found in the instruction (mfg opinion) book where it states that by widening the opening in F-2 you can use a 10 oz. tank. I'm still not sure if I want the Saito 72 or the 56. I think the 56 is more to my stile of flying, but it would be nice to crank that 72 every now and again. I will probably enlage the rudder and elevator and clip the wing.