Front Bearings on the way out?

[Adrian Smith 1]

Just confirm something for me folks as I fear the front bearings of my OS 120FS pumper might be knackered. The engine is in a Cmpro Extra 300S airframe and has done just over 10 1/2 hours flight time which I don't consider very long.

I noticed upon removing the cowl that the prop driver was covered in a rusty looking liquid, that wiped off, and was sprayed on the front internals of the cowl.

The prop shaft doesn't appear to have any "play" and compression is as normal. The last flight recently seemed as normal and with no funny noise with the tach registering a usual 8600 revs on a 14x10 prop.

Given the relatively little use I am wondering if the engines has suffered from some lean runs although the engine/crankcase are very clean and no burn't residue is apparent.

Looks an expensive job to me though.

 

 

[BB]

Don't know if this helps Adrian,

 

OS fs-52 Dissassembly

 

or

 

OS fs-52 Re-Assembly Pt2

 

 

BB

Edited By Basildon Biggles on 16/02/2010 17:25:51

[ken anderson.]

hello adrian-the symptons of  a 'knackered' front bearing -be it 2st or 4st..are normally the bearing feeling as if it is full of sand when turning the engine over by hand(feel's rough)..when turning instead of nice and smooth ---- or making a 'whineing'noise when running...this is when the bearing is near to falling to bit's normally.....what you are describing sounds like old 'gunge'.....from the inside of the crankcase from a previous session.....try some after run oil in the crankcase after you have finished for the day-if you are not going to use the engine for a while.......

 

         ken anderson.....

[Peter Miller]

You could be suffering from internal corrosion.

 

Bearings are not too expensive, You can buy them quite cheaply at any bearing stockist and they will be just as good. You pay for the OS label on the package.

 

I bought my last lot from "Simply Bearings Ltd" on the internet. they also take Paypal. Fast delivery over the Christmas break. These were for an Enya 46-4C the bearings were SKF so top quality, price was way down on the manucaturers spares.

[Adrian Smith 1]

Thanks for the feedback chaps. I think you may be right Ken as it was a couple of months since the previous flight. BB the links were interesting hopefully I won't need to go that route but better prepared.........

Will watch points on the next flight but thus far there has been no sign of "whineing" of a gritty feel so I may be being over cautious. Will let you know next time out. 

[TAIL DRAGGER]

On my last flight 2 weks ago ,i was just flicking the prop over and it felt like catching internaly it started ok  ran fine but did throw out some black gungealong with the usual  oil the en   gine is .40lc  any one got any ideas what it could be? cheers TD sorry i've put this on the wrong thread .

Edited By TAIL DRAGGER on 05/03/2010 14:52:09

[Stephen Grigg]

Could it be the piston reaching the narrowest point of the bore,which will feel very tight as it should be very tight

[Aslan]

it's ringed.

[TAIL DRAGGER]

OK thanks ,but what about the black gunge ? it's never done that before .  TD