glowfuel

Hello,

Have an OS 32 SX with about 100 flights on it.

I run S&W 15 nitro, 10x6 APC prop and OS A3 plug.

Am very strick with adding after run oil.

Lately, have noticed a slight 'whoooshing' sound while flying.

Tought, it maybe a bearing, but the prop turns by itself in a slight breeze (like it was new) with no stiffness or roughness felt in the bearings.

Perhaps it was the needle valve setting? It was leaned out for peak power during that flight.

Wish I could recheck it, but it's winter here in PA right now.


The engine starts very easily and is a true powerhouse, with no loss in power detected.


Any ideas?

Mr Cox

I don't really no what a whoosing sound is but you could check the prop for dents or replace it just to see if the sound changes...

kersplat

I have heard the same from different prop/engine combinations. I have determined from mine, that it was prop noise. I have heard this from bushing engines as well as ball raced engined.

glowfuel

Thanks Guys....