mbusch

My Feedback: (2)

I have a YS 120 AC turning a Master Air Screw 16/8 prop 8300 rpm at full throttle using Powermaster 20/20.

I purchased this engine used, but it had just come back from YS after having all the gaskets replaced and had not been run since.

The largest engine I have had till now was a 91 4-Stroke. This engine runs great and has plenty of power, I am very happy with it.

My question is what is the normal fuel comsumption for this engine? I ran it at the field ( tied to a post ) at 3/4 throttle and the 17.5 oz tank ran out in 9 min. That is almost 2 oz. per min.
Is this normal?

Dave Shadel

The fuel use is very high. Try leaning the high speed needle in a bit. It should turn the prop you are using faster than 8300. Even our newest 140L only uses 2oz. per minute. I suspect you are just way too rich.

mbusch

My Feedback: (2)

We used a tach to bring the engine to peak then richened it up about 1/4 turn. What should I expect to get for peck RPM. Also is a 16/8 prop the best choice

Thanks for the help
Mike B.

Dave Shadel

You should run the engine between 8500 and 9000. You are close with the 16x8, but a 15x10 might work better. Why did you run the engine at 3/4 throttle during the test?

mbusch

My Feedback: (2)

I normally do not fly at full throttle and was trying to get a safe time for a normal flight . Pryor to the test I had flowen at full throttle for 5 min and landed then took the wing off to see how much fuel was left in the tank, aprox 3/16 was left.

I think this engine runs great and just need to adjust my flight time for this engine.

I will try the 15/10 prop and see how it works.

Thanks again for your help
Mike B.