I just bought a used YS120SF at a swap meet. I would like to hear what RPMs, and props you are using. I will be using YS20/20 fuel. This is my first YS. Thank you.

I have been flying YS 1.20SF for a long time! My favorite prop is a 16 XC 8 APC, turning just at 9,000. The engine runs strong at this RPM and I like to idle at about 2200. It is not recommended to run the engine above this RPM. Did you get the owners manual (sheet) with the engine?
Good luck with it. Just remembered when I bought my first YS 1.20 1988. I still have it too. The fuel pump diaphram is the most suseptable part for trouble.
Bob
[email protected]

Bob, Thanks for your response. Yes, I have the manual and even the box! I was looking at an APC 16x8 or 17x6. Thanks again.

Andrew

Woohoo, there is not much that a YS cant solve. My Ultimate is a different machine! I got the following RPMs at 600 ft 80 degrees and Performance Plus YS20/20:
APC 15x10 8900 14.5 pounds
APC 16x8 9000 15.0 pounds
APC 17x6 9100 16.0 pounds
Thrust was measured using a spring fish scale. I am going with the 17x6 on my 10.5 pound CG Ultimate. All of my future engine purchases just might be YS instead of OS.

Gry101,
Those are outstanding RPM figures ! Your spinning the APC 16x8 about 1K more than my YS110FZ (I'm using 10% nitro)! Is the YS120SF the old 120 sport engine by YS, or is it a special edition version. Again, those figures ROCK!
Dennis

Dennis,

As far as I know it is just the standard 120SF YS part number 0070. I am not familiar at all with YS engine as this is my first one, specially the older ones. I would go with the 20% nitro, I know it is more expensive (15% @ $12.50 vs 20% @ $14 per gallon), but I got about 300 more RPM than I had with 15%. Try a 16x6, 16x7, or 15x8 on your 110, it might be a little happier, and on 20% nitro....
Andrew

ANDREW

How do you spell PERFORMANCE 4-STROKE "YS".
I used to be an OS 4-stroke flyer and even still have a couple (in the BOX)
My CG Ultimate has a 120SF on it and it too much fun to fly. I have a Tru Turn 3 blade Ultimate spinner on it and use a Gropner or Master Airscrew 14X7 prop.
Doesn't perform like the 16X8, but sure looks cool when taxiing and shut down.
I will add the plane to my Galery.

Bob
[email protected]
AMA 1548

Well you can belive it if you want but my Ys120SC will turn 10.5k Rpm with the APC 17x6 prop if its tweaked out, but normally take off with it turning around 10/10.2. This is with either 20/20 or 30/18. Been running it for 4 years, also even ran a 16x6 for about 20 flights.

Justin