AMB

OK GROUP Maybe repeating myself have 50 plus engine most are diesel or diesel conversions and 8 or 9 4 strk glow I have never lost a bearing in any engine,or rust the 4 strokes
get a short run on model diesel fuel (plug energized) they might sit for a year or more gummy sometimes a quick rinse with diesel fuel solves the issue
on one of my OS instruction sheets it states rinse well with KEROSENE and then store in plastic bag if storing fror a period of time
PE Reivers suggestion of" how to" is a good one also- martin

If you check the diesel site you never see this come up, failures sure, broken cranks, egged out rods, thats about it

Lightspeed1551

My Feedback: (4)

Ware as the engine made? Some of the newer OS engines are being made in China. Low quality china bearings could be the source of the rust.

JollyPopper

My Feedback: (6)

To get back to the OP's question, it smells like smoke to me. For bearings with that little time on them to fail, he would almost have to be putting something corrosive in the engine between runs to achieve it. BS

airraptor

My Feedback: (66)

+1

dingo9882

I have an OS 120 AX that eats bearing every 50 flights or so. I thought it was something I was doing until I found out a whole lot of other people were having the same problem. I replace bearings in that engine twice. Then the third time I switched to Boca bearings, I got the high performance speed bearings so far so good. It is very possible it was rust, but I have never heard of that before but it is possible. Maybe moisture got in there some how from your fuel or whatever I am not sure though. You said you live in a very dry climate I am not sure how else moisture could get in there to cause the oxidizing of the metal except from maybe a bad batch of fuel.

Lifer

My Feedback: (1)

Several years ago I was using a fuel that had extreme pressure additives, which was explained to me were chlorine based. Good for wear protection but promoted rust if not cleaned off after running. A friend heard of the problem and gave me a can of "Corrosion X." No rust issues since, in over 15 years. Hope this helps.

bjr_93tz

I'm not going to pass any judgment on what Jaka's doing with his fuel and engines and I thank him for the pictures. However I've never seen a rear bearing AND crankshaft look so rusty in anything I've ever run.

Here's a couple of photo's of the three bearings I've pulled from my YS DZ170 pattern motor at the end of each season. The one one the left has a few rust spots but it's mainly oil staining and it has been sitting in a bag (straight as removed from the engine) for at least 2 years.

Fuel is home brew 10% coolpower blue oil, 20% nitro (cheapest stuff) and 70% methanol (industrial stuff nothing fancy). Motor gets irregular running and can be a few weeks between flights, then 4-5 flights/day when I have the time to practice. Never run the fuel out and never put after run oil in it and lugging an 18.5x12 prop. Everything in the cooler parts of the engine has like a thin green/blue film over it that wipes off with a finger.. I believe Koyo are a good bearing though, and OEM for my engine...

Hobbsy

My Feedback: (102)

Corrosion X is the best after run oil of all, bar none. Not only is rust prevented but keeps engines as clean as new inside.

controlliner

I don't use after run oil, ever. I have plane and car engines, none of them have rusted bearings. I believe using ARO strips the surface of any rust preventative ingredients and causes rust. I use Omega 10%. I also believe that the higher nitromethane fuels (which I don't use) have a higher incidence of rusting.

fizzwater2

My Feedback: (61)

Hobbsy - do you buy it in the 16oz bottle with the sprayer top, or is the smaller bottle packaged for firearms the same stuff?

Or, do you buy the spray cans? Just wondering..

ovationdave

My Feedback: (16)

The description for corrosion X is the same for three products: Corrosion X, Corrosion X Aviation, and Corrosion X for Guns. I don't know what the difference is, but I have used Corrosin X (red aerosol can) for years for Long Term engine storage. I don't use it as a regular after-run oil, however I am sure it would work well for that if you used it that way. I do know that my aerosol can eventually lost its pressure and I had to empty the can into a bottle to continue using it. I would prefer to by it in a bottle but the only one that I see like that is corrosion x for Guns.

Dave

camsbad

Sport_Pilot ...You should educate yourself before making a statement like the following:

"We are talking about a two stroke, there are no combustion products in contact with the crankshaft of a two stroke."

Please go take a basic mechanics course at your local community college or the local high school before making any more statements about any engine or how it operates.

Why do you think that there is oil in the fuel we use in the glow engine? It's there to lubricate the entire engine, including the crankshaft, and bearings, and cylinder and piston(s).

airraptor

My Feedback: (66)

I never use after run oil and never will!

look up the OS 140 engine and what all the Pro's did soon. On every new engine the would remove the stock bearings and replace them.

Texastbird

I had a 61FX peel the liner real bad after only a few flights. I sent it in under warranty and they told me the bearing had rusted causing the destruction of the liner. Total rubbish of course, but they did replace the engine. The best way to prevent corrosion in a glow motor is to follow Pe's recipe and run the engine on it long enough to get the contaminates out of the lower parts of the engine. It only takes a few minutes at the end of the day. I use lighter fluid because its easy to find and a mixture of transmission fluid and Marvel mystery oil. Just pouring some oil in the engine does nothing to flush the nitro out of the engine. But burning it out and replacing it with the naptha and oil mixture really does the trick.

controlliner

He knows that there is always a fresh charge of fuel entering the crank case. What he is stating is that there is no spent fuel residue entering the crank case like in a model four cycle engine.

fly24-7

I'm no engine expert, but it's hard to believe that rust would build up that quickly to the point of killing the engine. I have multiple engines that are 5+ years old. I run Omega fuel and burn off as much of the residual fuel in the engine as I can at the end of each flying day. I do nothing special in the winter when the planes sit in the basement. Just leave them dry. I've never had a problem getting an engine running again in the spring.

I have to say I have no idea what these engines look like on the inside because the only thing I've done maintenance-wise is replace spent glow plugs. They run strong and start very reliably. So, it sounds to me like the hobby services guys are reading you a line out of some troubleshooting manual. It doesn't make sense to me that an engine would go bad that soon unless there's a defect in it or it was badly abused.

MJD

My Feedback: (1)

No way... really?

We're all happy that you took basic mechanics, obviously you excelled at the subject. Perhaps you could take a minute to explain the operation of a 2 stroke front intake glow engine for the rest of us who don't get it? I always thought combustion took place in the combustion chamber, and the combustion products went out through the exhaust port - but evidently I have it all backwards like Sport_Pilot.

Maybe next time proof read your post before sending. Or take reading comprehension at the local community college.

controlliner

Eating Popcorn

Sport_Pilot

You are the one who needs a mechanics course, or maybe english course, not sure which. The burned nitro and burned methanol (combustion products) go out the exhaust, thus the nitric acid never touch's the internals of a two stroke.

earlwb

I have remembered that a few people had mentioned that they may have chosen the wrong bearing size as well as specified the wrong type of  bearings to use as well.  Probably some accountant types got in the way using it as a cost cutting measure.  Not all ball bearings are the same. They may look the same visually, but there are quite a few subtle differences in their designs and how they work too. 

ovationdave

My Feedback: (16)

Pass the butter please!

donalddrew

PE Reivers wrote "the end user is to blame, mainly because he did not get the proper instructions to keep his engine free of corrosion after he shut it down at the field.
EVERYbody knows about the use of "after run"treatment", unless you are a novice at running glow engines. (here lies the problem)"
Perhaps he didn't read my original post. 2 or so month's I've been flying this plane a couple of time/week over the 2 months I've had it. (so it doesn't sit around) I do run the engine dry at the end of each day. Drain the fuel and run the engine til it quits. Then with the glow plug driver attached turn it over with an electric started several more times. Then put (as per instructions on afterrun oil) several drops ARO into carb and through glow plug hole. Then turn over engine again with electric starter. It seems to me that perhaps "EVERYbody" doesn't know about the use of afterrun treatment.. Several of the posters state they never run after run oil. And if you speak with the folks at Morgan Fuels, they say you don't need to use ARO with their fuels. So what I surmise from the posts so far: Possible a bad bearing/cheper bearing materialfrom the start, remove back cover to check for rust before sending to Hobby Services, ARO certainly won't hurt, run engine dry at end of day.

aspeed

I am going out on a limb here and saying OS should stand behind their choice in lousy bearings.  I never used after run oil in any motors for 40 years unless using nitro over 10% nitro, with no problems with rusty bearings.  I have had a bit of rust on crankshafts that came off with steel wool/fine sandpaper, and have only replaced bearings on swap meet and garage sale motors.  There is always the choice of plain bearing motors too.

ovationdave

My Feedback: (16)

I have to say, I know some have been razzing this issue a bit, but in all honesty, at the end of a flying day, for YEARS, all I did was empty my tank, wipe off my planes, and load up. I have NEVER had an issue with my engines. No ARO ever.

Its a faulty product. Plain an simple.

~Dave

blw

My Feedback: (3)

You didn't mention bushed connecting rod ends.