OS50 Bearing replacement - part 1

[richieclarkie]

Checked the main and header tank clunk pipes and found (as I suspected) the main tank clunk pipe was shot, strangely though the header is fine.

The reason is the exhaust gasses don't make it to the header. It is the exhaust gasses that eat away at the fuel tubing. A good way to extend the life of the clunk is to fuel up at the end your flying session and either leave the fuel in the tank or drain it again. This will push out the gasses out of the tank.

[richieclarkie]

For those interested attached is a (rather poor) pic taken on my blackberry of the old bearings



Thanks all for the help and advice

Looking at you back bearing I would consider doing the following if you don't already:

1) Run your engine dry. Clip the fuel line at the end of the day and turn it over with the glow plug lit. Let it run until it won't run anymore. That way you know all the fuel is burned and just oil remains.
2) Ensure that you store your heli in a dry place. Sheds and garages are not normally dry so inside is preferable.
3) If you don't fly your heli for a couple of weeks remove the backplate and drop some afterrun oil in.
4) Some fuels seem to look after your bearings better than others. It may be worth considering changing fuel depending on what you use now.

[Janek]

Looking at you back bearing I would consider doing the following if you don't already:

1) Run your engine dry. Clip the fuel line at the end of the day and turn it over with the glow plug lit. Let it run until it won't run anymore. That way you know all the fuel is burned and just oil remains.

IMO this is a waste of time, I used to do this, but now don't, and it has made no noticeable difference to the life of my engine bearings.

It's not the unburnt Nitro, or Fuel, that causes the "rusting", it's the exhaust gasses and residues, and this process does not remove those from the crankcase.