YS Peak power

[Turbo Dave]

What engine RPM would a YS make its Peak power at?

Running 8.18 in my Stratus and want to know what headspeed to set my GV-1 at, and comment appreciated.

[DavidH]

I found the engine likes to run in the mid 14K rpm range.
I would set 1750 to 1800.


David

[3D Heli ireland]

I'm running mine on 8.45 to 1 which is the recommended ration for the YS on the Stratus with a headspeed approx 1900 maybe slightly higher. That works out to be 16000 to 16500. I suppose then on 8.18 to 1 you are looking about 1950 plus :!: which is getting into dangerous territory.

If you really really want the peak power from that engine at a realistic headspeed change your ratio to 8.45

I have always found the YS 91 likes to run hard. I have run this way for years now on more than one heli and it works just great. The only thing is I am into 3D, maybe you are not.

[Turbo Dave]

Yeah I thought the YS liked to rev harder than the OS from what I have heard, I currently run the OS at 1950/8.18=15951.

[G MAN]

I am currentky usung the 8.18 ratio and running the headspeed at 1950 with 710 Radix blades on my YS 91 Stratus. The YS like a little more RPM than the OS because of the higher port timming.DOUG