OS .91FX for Four-Star 60
 

Hello. Just ordered a Four-Star 60 and I am leaning towards powering it with a .91FX seeing how it shares the same footprint with the .61FX. Any ideas/opinions on this? Is this going to be too much power for this plane? I was wanting this engine for Top Flites P-47 anway.

RE: OS .91FX for Four-Star 60
 

The 91FX will swing a 14 or 15" prop well with good power, and use quite a bit of fuel. I would save the the 91 for the warbird and find another engine for the 4* as it is a sunday type flyer, meaning it does not 3D well so no need for a lot of power, besides a lighter bird flys better. Any good 60-70 size motor will fly the 4* great.

RE: OS .91FX for Four-Star 60
 

This depends on your skill. The engine is not too much. I have had 2 4-Star 60s, both bashed into Kawasaki Tonys, powered with an OS .91FX and a Magnum .91XLS. Both had Ultra Thrust mufflers for more rpm on 14-6 APC props. Both had excellent vertical-as far as you want. Landing was still slow and easy. I did more the main gear to the wings for a more scale look.

You can also run the OS on a 13-6 or a 12-8 and let it rev. The .91 makes it a whole different airplane.

RE: OS .91FX for Four-Star 60
 

If you want power then don't fool with a 91FX, get a YS, Jett or Saito and be done with it. The 4 star series of planes were not designed for 3D. One can hang a trainer on the prop with enough power, but that does not necessarly make it a good 3D bird. Likewise installing a heaver engine than is necessary is defeating the purpose of a light great flying plane.

RE: OS .91FX for Four-Star 60
 

Thanks for the input Taildragger. I think I will go ahead with the .61FX. I have not decided on the .91FX for the TF P-47 anyway. I might just 4-stroke it instead. I am building the Four-Star for more building and tail-dragger experience as this is only my second kit. My first was the Tower Hobbies Fun-51 and I also bought a Sig Something Extra kit along with the Four-Star. Should keep me busy this winter along with the other projects I have going.

RE: OS .91FX for Four-Star 60
 

You might want to consider the OS91 surpass. I fly my 4*60 with one and it is a great combination. As indicated, the 4* is not a 3D plane, and the surpass gives it plenty of power for most aerobatics. Some have even taken off the outside bay on the wings to get greater roll rates, but I fly mine stock and enjoy it for what it is.

RE: OS .91FX for Four-Star 60
 

The 91fx is the same weight as the 61.There is no weight penalty over a 61fx.
I would go for the 91.Same weight but more power.Thats a no-brainer to me.

RE: OS .91FX for Four-Star 60
 

Go ahead and install a 91FX, you will probally have to get longer gear so the larger prop will clear, then there is the expense of the fuel for the 91FX which is a fuel hog at 10 flights of 12 min for a gallon of 15%. Yes power cost money, but we love to over power everything.:D

RE: OS .91FX for Four-Star 60
 

Yu should be fine with the standard gear, as long as the prop is 14".

RE: OS .91FX for Four-Star 60
 

I am flying a 4 star 60 with a OS 91 FS with pump and It is a hoot, fantastic combination. I would think a .90 2 stroke would be equally impressive:D