[quote]ORIGINAL: jnesbitt82

Hello everyone, I went to fly today and I started my plane with the electric starter. It fired right up and I throttled back to much and killed it. when I cranked it with the starter again the prop and spinner broke loose spun around the shaft and flew off[] This also happened on my second flight with this plane. I know I tightend it enough. So what am I doing wrong?

>
>What is happening is that the engine is "kicking back" (also called backfiring).
>Since this happened twice in 2 flights, it sounds like your engine MAY be
>running too lean.
>
>The easiest way to check this is:
>
>After the engine is started and the glow starter is disconnected, advance
>the throttle to wide open and point the nose of the plane straight up. If
>there is no change in RPMs, it is adjusted properly. If it speeds up
>and/or dies, it is too lean. You need to open the high speed needle valve
>about 1/8 - 1/4 turn and repeat. If the engine slows down and/or
>"blubbers", it is too rich. You need to close the high speed needle valve
>1/8 - 1/4 turn and repeat the nose up test.

>Things you can do to minimize/prevent the prop from coming loose/off is:
>
>Cut a piece of sandpaper (100 grit is good) to fit between the back of the
>prop and the thrust washer. Have the grit side of the sandpaper towards
>the prop and tighten the prop as usual.
>
>Add a safety nut. This would be a second nut in front of the one that
>holds your prop on and tighten this nut against the first one FIRMLY.
>You may not be able to do this with all spinners.
>

also, I bought two new props for my plane, both 10x6 one is plastic like the original and the other is wood. What is the real differance between the plastic and wood props?

>
>Wood props tend to flex less than plastic props when under a load. The
>downside to wood is they WILL BREAK if the prop has ANY TYPE of prop
>strike. Since you are just learning, I would suggest using a Windsor
>Master Airscrew 11x6 prop. These are the black ones. They are
>substantially more tolerant of a prop strike. Once you have learned how
>to land, switch to an >APC 11x5, 6, or 7. I would not run a 10x6 prop on
>a 46 engine (unless you are racing, but that is another story). There is
>too much chance of the engine over revving due to the lack of a proper
>load on the engine.
>

What is the differance between a flat ended prop(both new ones) and a tapered ended prop(the original)? Thanks guys

>
>The tapered end prop is USUALLY a more efficient prop AND it is a quieter
>prop. Switching from Master Airscrew props to APC props frequently results
>in a drop of up to 6 db in the noise level generated. In many communities
>noise is a major issue and strictly enforced at the flying field.
>

[quoted]

Hope this answers your questions.