WiLL-3D

Hey there!

Am currently flying a phoenix models sukhoi su-31. I am running it with a thunder tider gp.42 which is kinda underpowered for that heavy plane. I decided that I might be getting a bigger engine for that plane with loads of power and that at the meantime it would help the problem that my plane is really tail heavey. Even with the tank full the plane is completely dropped to the back. I was thinking about maybe an O.S FS-70 II but then I noticed its not that much of an over power how I like and I might be getting a little heavier 40 size plane in some time. Now am thinking about a O.S FS-91 II for my plane but I have noticed that for a couple bucks more I can get a saito 100 which is lighter and even more powerful. I would appreciate you guys to help me choose the engine. I really want a reliable strong engine (looking for a 4 stroke since I fly scale models) that wont be making me all angry at the track cuz I cant get it to turn on or I cant get it to run porpperly or maybe its shutting off oftenly. Your guys help and opinions would be very appreciated!

Thanks,

Willie

Harry Lagman

The OS Surpass 2 .91 and the Saito FA 100 are both great engines. The Saito is lighter and pulls bigger props a little better than the OS because of its larger capacity but when both are propped optimally, their performance is similar. The OS is more economical and is perhaps the most consistent, durable and dependable engine in the known universe.

Get whichever engine balances the plane.

speedster 1919

My Feedback: (3)

First I would put a heavy hub nut on engine to balance plane. Once balanced I would make a power judgement. That model is a 40 size and a 91 or 100 would tear its guts out. A 72 or 82 Saito or 70 Magnum would be better.The OS 70 is know for tuning issues. A Super Tigre 51 would be perfect for 2 stroke. It weighs more than GP42 and does not like high nitro content........

Fastsky

If you want good power and a user friendly engine I would suggest either a Os 46 AX or a Thunder Tiger Pro 46. The OS is a bit stronger engine but the TT is less pricy. Both are super easy to tune and very reliable. [8D]

WiLL-3D

I am mostly getting a bigger engine because I really like having lots of power and that nice unlimited vertical but I also thought it might help my tail heavy problem. Now am thinking between an O.S .61 FX or maybe an O.S FS-70 or FS-90. I know the O.S 61 FX is a flawless engine and has tons of power because my dad owns one, but how about these 4 strokes? What is the common maintanance I have to give to them? What are the common problems they give?. I really like the sound of those surprass engines but if they come in too expensive or are too much trouble I'll stick to the 2 strokes.

Thanks for the reply's!

Willie

w8ye

My Feedback: (16)

The OS Four Stroke Surpass II 70 and 91 are powerful flawless engines also. I'm sure you will enjoy them.

The OS Ultimate 70 has had problems in the past. I don't know about the new ones?

The OS FL70 has had mixed feelings from modelers. It is just a sport engine. With that said, it serves it's intended purpose well.

wcmorrison

My Feedback: (2)

Both four stroke and two stroke engines are fairly simple, though the four stroke has more moving parts. Many folks like the sound of a four stroke, sounds more like a real reciprocating airplane. The four stroke has tappets that need to be adjusted but that is not hard to do and you do it maybe once a year. Both can use the same fuels

The four stroke responds to the throttle a little better than a two stroke. Both generally have the same kind of carb, that is a twin needle carb. The OS FL-70 does not and as previously referred to as just a "sport engine." I like the Surpass II 70 and think the Surpass 90 or Saito 91 or 100 as to big for your airplane (it will cause the fire wall to eventually fail).

You probably will be better off with a Super Tiger 51 or an OS 61 two cycle engines. The Super Tiger is a ripper, really goes, but does need about a gallon of fuel thru it before it starts to really perform.

Good luck,

Cheers,

Chip

WiLL-3D

An O.S 61 FX pulls the plane better than a O.S FS-70 right? I think that if the 91 is too much power these are my last 2 options.

Thanks,

Willie