I am trying to make an engine decision for a 2M Pattern Plane I fly for non-competitive pattern flying fun. The only engine I have experience with is the OS1.40. I am thinking about getting another engine; but just can't see spending $650+ for a YS1.40D. Does anyong have experience with the YS1.40Sport and how it would compare to the OS1.40. thanks.

why not a webra or a 3M or the os 1.60.......i think the sport is alittle les powerfull than the RX.

The YS 140FZ Sport is a great motor. FOr comparison its very close to the 140L performance. I'm turning a 16-11 at 8800 on 30% heli Pro Cool Power.

Although it will less on the top end as the 140RX it will definitely have better throttle response. I have only seen one non-EFI OS 140 run with a good throttle response. It was running a Mixture control Carb. Not knocking the OS just I found it was not for me. I also have run the EFI and its a little better but not up to my standards.

The 140Sport is a little lower total power but has that great torque in the mid range that the 2 strokes lack. Also its basically like the original YS 140FZ but a little more power....because of a bigger carb opening. The Sport may have a name that tells you its not up to the competition level but it is more than up for the task. I would say if you're looking for great power in a a little cheaper package and you still get the 4 stroke qualities...the Sport is it!

I don't want to start a war on OS vs YS as you already know the OS is a very good motor. I just found like many other pilots the 4 stroke much easier to control. The comment I have heard by a top pilot was "the power was great, I sure wish I could control it! It was almost an all or nothing kind of situation"

For a little incentive I heard Central is Selling the Sport at $400 so its even cheaper than the OS now...and its Cheaper than any of the 120's of recent years....

The DZ's are what the top guys are running. I know the world seems to be going to the 2 strokes...But still 8 out of the top 10 at the worlds were the YS motors. And that was with Jason running Electric. If you look at the top 20 its probably 15-16 of them using the 4 stroke...There is a reason. Throttle PERFORMANCE...I know you're not looking to compete but my guess is you're are looking for the performance of a competition model.

Bottom line I don't think you'll be sorry one bit going with the Sport...It may Surprise you a little how well it performs.


As you will note I'm bias, but its only because I have ran them all and went back to what worked for me.


Troy Newman
-YS Performance Field Rep.

i'm not meaning to fight back but, i've never had a 2s (over a .46) with bad throttle responce one of my friends runs the RX and it has perfect response just as good as the 140L.....i am going to put a mintor in my next 2M and from what i've heard its hard to break in but then it runs really good.

Good info so far.

Let me provide a little more information. I have some large glow 4s and 2s experience. I have the OS1.40RX in a plane and I really like it. However, I am thinking about getting a new plane. I would like to try 4s. The new plane weighs the same as the old, around 9.6 pounds. I am wonder ing about the 2s-4s power ration issue. I.e., it usually takes a 4s of higher cpacity than a 2s to produce equal power. So I am asking for help on this issue and to confirm that the YS1.40Sport is not underpowered compared to the OS1.40RX


while, I'm at it. Deos anyone ever use a Saito.

the 4s have just as good power but are alittle heavyer and they have more torqe. a 4s or 2s will power a 9.5 pound plane really well.