Bearing rust

[hydev]

Hi,

Just had to replace my front/rear bearings due to rust. Does anyone have any tricks to prevent or slow this down? Does after run oil help or is it marketing? Fairly new to nitro but not helis so any help would be greatly appreciated.

Mike

[mdu6]

Rust in the front bearing is very rare - never seen one rusted in my case unless you are talking about rust in the inner sleeve which can develop because of the contact with the crankshaft, which is not a big problem.

The rear bearing is a different story - I guess it is one of the most talked about issue in the nitro world since the advent of the 90 size engine. In my case after trying all bearing types and magic oils - I simply turned to the Magnum centerglide bearing (oilite bushing).

I currently have an OS91-HZR that has 3 years 700+ flights with this setup. I even sent a new engine in this winter prior to running it to get the bushing installed.

[Arclight338]

I found that after flying I pull the glow plug,drain the fuel and spin the starter to blow the fuel out of the cylinder. Then I pull the back plate and let the excess oil drain into a lint free cloth,with the heli upright for an hour or so. After that a FEW DROPS(that all-NOT alot) of Marvel Mystery Oil or automatic trans fluid into the rear bearing and on the cylinder liner and spin the motor to distribute it. Put on the back cover.Reinstall your glow plug. You are done!

You are now safe to let the motor sit for as long as you wish. Regardless of fuel-part of the combustion process is water vapor-you HAVE to get that out of the motor. Period. Just using after run oil isn't enough. Another important factor is absolutely NO oil in the carb or regulator(if the engine has one), the silicone will deteriorate. Only clean fuel is safe to use there.

Although I own a few electrics-I rarely fly them. I'm a Nitro addict!! If I don't get to the field due to weather( brutal winter here in New Jerseystan) I give the stored motor a few turns with a starter wand by hand just to prevent the ring from sticking.

That may seem like a P.I.T.A. but it beats replacing rear bearings due to rust. I run Torco,Coolpower and VP powermaster 30%. No fuel will replace simple maintenance. PS: I agree with mdu6-rust in the FRONT bearing is rare.

I've run nitro motors since the 1970's- cox 049's and realized that you can't run them and just put them away.

[steve_b]

At the end of a days flying I just spin the engine over with the glow driver attached, and the fuel line pinched, until the engine doesn't fire and there's no smoke coming out of the pipe. I then fill the tank and that's it.
I've just replaced a bearing that had around 150 flights on it and it looked fine, but was replaced while I had the engine stripped down to replace the ring.