Hirobonut Heliman Location: Arcadia, CA
| Engine ChoiceRichard,
I have finally put together the OS91 in a regula Freya with Hatori muffler (part number 980) 12T pinion and 93T main gear, and a set of MS 680 3D blades.
I only burned 4 tanks of 15% fuel through it so far and boy I'm so amazed at the power. My needles are still set on the rich side (1 1/2 tunrs out) but when I punch the sticks, the heli does not hesitate at all.
As for the YS80. I put it in my Freya EX. I'm running the 12T pinion, 95T main gear, High volume Hatori muffler (part number 981), and 680 glass blades that comes with the kit.
Agiain I have only burned about 4 tanks of 30% fuel. It has more than enough power to put the EX through any kind of manuver, however compared to the OS 91 it does not have as much power.
Richard, both are great engines with the combination that I described above.
The pluses for the YS80 is that it is pressurized so you will get a very consistent run even if you decide to do crazy tumbles. Additionally you will get a very fine needle setting since it maintains the three needles that is seen on the YS 61 ST II. The drawbacks however is the cost in fuel to fly this engine since it does not like 15% at all.
As for the OS90 it has tremendous POWER and you will save a bunch on fuel costs since it runs just fine on 15% (I can't even imagine what kind of power you will get if you put 30% fuel in it). The engine runs very smooth, however it is not pressurized so you may want to get a header tank. As for the drawbacks, the engine is very hard to crank (I had to purchase a Sullivan Dynatron starter and use 24 Volts to crank this thing) and that OS has gone back to the 2 needle carb to save costs.
Hope that helps.
If you still can't decide, buy another EX and put an OS 91 in one and a YS 80 in another!!!!
Stanley |