Hi.
I want to replace a YS engine 53 FZ which is installed in my GP Extra300s 40 ARF with a hot 2str.engine.
So,i want you to tell me disadvantages and advantages between the engines i have in mind!
Also,due to personal experience,please tell me which engine to you prefer and why?
Thank you.
Engine selection:

1) OS 65 LA.
2) OS 61 FX.
3) OS 46 AX.
4) Supertigre G61 ringed.
5) Supertigre G61 ABC.

If this is a 40-sized plane and you don't already have a snot-load of nose-weight then go for the OS46. All the other engines are pretty heavy and that weight will offset the extra power they offer.

Besides, if you're going to put a 60 in a ship you might as well put a 90 in -- they're generally the same external size and weight but have more power so you can re-use them in a wider range of planes later.

But, for a 40-sized plane I'd stick with the OS or maybe a Thunder Tiger 46Pro

Kostas1,
Look at the Webra50, MVVS49, OS50SX, Irvine53, rossi53.
All these engines have good power/weight ratio, good carburetors and will last a long time[sm=thumbup.gif]

The wing area on a extra300 is not big enough to handle the extra weight of a 60-sized engine. Good luck

These engines weigh:
1) OS 65 la: 535g (18.9 oz)
2) OS 61 FX:23.6 oz
3) OS 46 AX:17.2oz (489g)
4) Supertigre 61 ringed:759g (26.8oz)
5) Supertigre 61 ABC:756g (26.7oz)

So,are they too heavy?
I mean this is a 40 size ARF and Greatplanes suggests 40-50 2str.engine.
I want unlimited vertical so an OS 46 AX is not a good option?[&:]
What engine for this type of flying(unlimited vertical power,hover etc.) do you suggest?

G'day
Kostas for a 40 size plane the 46 ax does give you unlimited vertical power. Speaking from experience I had one in a 40 size PC9 and just kept on going up and up and up and up and up. Provided that you treat the engine properly the 46 ax wil give you the performance that you need.

Also a fella at my local club had one of the GP extra 300s 40 size with a 46 ax and it would hover and pull out easily.[8D]

You mentioned HOT engines. Look at the Webra Speed .50 and Jett.

Dr.1

So,really?
An OS 46 AX can hover the Greatplanes EXTRA 300 40 ARF?
Sure?

I have an OS 46 that turns a 12x4 prop about 12000 rpm and produces a little over 6 lbs static thrust . I have hovered a 4 lb Burrito 3d plane with it. It is enough thrust for the plane but just barely. I now have an OS 50 on the plane and it is more fun. I have had a YS 63 on the plane , close to 9 lbs thrust and a little scary until you get used to it. Most of the guys on the 3d forums will tell you to get a Saito 82 for 40 size 3d.

I suspect your Extra weighs more than my Burrito so a 46 may be a little small for it. If I had the plane and a 46 engine I would fly it. If I were buying a new engine I would get at least a 50. No one can tell you if an engine will hover your plane unless you tell us how much the plane weighs.

Any of the 50 class european twostrokes will be good. I run a webra 50 with a pipe at 15000 on a apc 12-4

Hi.
I don't know weight,just it is a 40 size aerobat.