harryw13

I have a Airskipper 50, with a OS 50 Hyper engine. I have a throttle jockey pro to maintain RPM's, I'm running it around 18500-19000 RPM's. My pitch runs from about -10 to +10. I try to run the engine at about 210 degree's.
When I get to about 8-9 degree's of pitch the engine starts to bog down, and can't seem to maintain my RPM's.
This cause's me to lose altitude during flips.
Can I increase my RPM's? What's the limit?
Thanks

BarracudaHockey

My Feedback: (11)

Are you talking about the motor or the rotor RPM?

The hyper is best around 17000 rpm, on an 8.5 gear ratio thats 2000 rpm on the head, 1950 if you have an 8.7 gear ratio (not sure about the AS but one or the other is most 50's ive seen)

If you are bogging in flips you probably have too much cyclic pitch, set it up for about 7 degrees of cyclic throw and try it.

harryw13

My bad!!! I meant 1900 headspeed.
Are you saying max pitch 7 degrees?
Thanks

BarracudaHockey

My Feedback: (11)

Max cyclic throw. That hyper will pull +- 11 or 12 w/o bogging if its tuned right, 1900 is fine.

Set your collective to zero degrees. make sure the swash is level and put the blades out fore/aft and stick a pitch gauge on it and give it full right or left aileron and read it, do both ways it should be the same, you are looking for 7 degrees. Any more reduce your end points.

Turn the head 90 degrees so they are out left and right and do the elevator. My guess is too much cyclic, like 9 degrees or so.

harryw13

When you say "tuned right". What do you mean? Other than setting the needle valve, is there something else. I have been running a cylinder head temp. of around 205-220.
From a hover, the engine starts to bog down when I reach about 8 degree's pitch.
Thanks