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.