benweager

Hi,
I wish to replace the bearings in a second hand OS FS-160 Gemini as they show signs of corrosion.
I would like some advice on dismantling the engine.
I have so far removed the rear case and one cylinder head.
The timing gears have some slight corrosion but teeth look acceptable.
The cylinder looks good and the bores show no wear or corrosion.
The crankshaft rear bearing looks bad so I suspect I need to replace all bearings.
I am not sure of the dis-assembly sequence or how to remove the crankshaft without damaging it and would appreciate advice on this.

Bax

My Feedback: (11)

Once the cylinders are removed from the case, remove the connecting rods. They have small hex screw holding the rod bottoms onto the main rod. Make sure you mark them so you can reassemble them in the same place with the same orientation. Remove the cam followers. The camshaft will exit the case directly aft. The crankshaft will, too. You can clean them up with some penetrating oil and four-ought (0000) steel wool or 600-grit wet/dry sandpaper.

You can download an exploded diagram from:

http://www.osengines.com/parts/exploded-views.html

benweager

Thanks Bill,
Very helpful, one more query, should I need to heat the crankcase and crankshaft assembly to ease removal of the crankshaft and rear bearing?
Cheers,
Ben

Bax

My Feedback: (11)

The crank can be removed without heat. You'll need to heat the case to get the bearings out. Clean the case and reheat to install the new bearings. Don't put any pressure on the balls or inner race when you install the new bearings. Only against the outer race...otherwise, they'll get damaged.

benweager

Thanks Bill
All went well with dis-assembly
Ben

VE3-Flyer

Good Day Bill, was on the Rc Uni site looking for info re OS FT 160! I saw several posts you were involved with (a while ago) re changing the bearings! I have one of these engines with noisy bearings! The engine runs but the bearings fell corroded when you turn the prop! I downloaded the manual looking at the exploited view of the engine and the gear system looks pretty straight forward, its just the timing marks putting it back together! I have done several Saito engines NP, this will be my first OS and a twin! Hoping you had some suggestions, thoughts or what out for if you pull off the back cover! Thanks for reading ................Cheers ............Rudie

VE3-Flyer

Good Day Bill, was on the Rc Uni site looking for info re OS FT 160! I saw several posts you were involved with (a while ago) re changing the bearings! I have one of these engines with noisy bearings! The engine runs but the bearings fell corroded when you turn the prop! I downloaded the manual looking at the exploited view of the engine and the gear system looks pretty straight forward, its just the timing marks putting it back together! I have done several Saito engines NP, this will be my first OS and a twin! Hoping you had some suggestions, thoughts or what out for if you pull off the back cover! Thanks for reading ................Cheers ............Rudie

fotoreb

Changed all my bearings in my 160 gemini..v1
back 6904 (37x20x9)
middle os130 (28x13x6,4)
Front R6zz (22,2x9,3x7,1)
Front cam shaft (17x6x6
Rear cam shaft (17x9x5)