After Run Oil?

After Run Oil?
I only have four engines all of them OS. One of them was given to me by my father who flew it for many years. All of them have logged many
hours with perfect reliability and absolutely no problems. I firmly believe that OS products will last at least as long as me - perhaps longer!
Accidents happen and usually the engine takes the hit plowing into the ground. From my observations, the planes don't survive, but the engines do. These incidents are a testament to the incredible quality of these little engines.
If you happen to plow your engine into the ground, there are a couple of things you should do.
1. Don't panic. OS model plane engines can take incredible abuse and still be mechanically fine.
2. Don't turn over the engine. Doing this will distribute any dirt the carburetor caught throughout the engine.
3. Don't disassemble the engine while it's under warranty. If you suspect any problems, return it to the manufacturer. Often times they'll inspect and make any repairs gratis.
4. Do brush off any exterior dirt.
5. Carefully remove any dirt in the carburetor intake. I have used a stim-u-dent tooth pick and a small water color paint brush. With the engine upside down and using a fuel bulb, lightly wash out the carburetor intake.
6. Now that you have done all that you can do try turning the engine over with the plug removed. Listen carefully for any strange sounds. If dirt has gotten in the bearings, you may hear a grinding sound. If you have any doubts, read #3.
Now we get to the issue of after run oil. The newest engine I have is an OS 40 LA which is a great little motor. On page 28 of the instruction manual, which you can verify for yourself, Max says:
"If the engine is not in use for a while (more than two months) remove the glow plug and rinse out the interior with kerosene (not gasoline), by rotating the crankshaft. Shake out the residue, then inject light machine-oil through the plug hole and carburetor intake, again rotating the shaft to distribute the protective oil to all working parts. Gasoline, thinner, kerosene, and light machine oil cause swelling and deterioration of plastic parts, "O" rings and fuel tubing. Use methanol for cleaning these parts."
This paragraph implies a few things. First if you're regularly flying your engine, you don't need to do any special maintenance. OS does caution about leaving any raw fuel in the engine in paragraph #3:
"Do not leave raw fuel in the engine at the conclusion of a flying session: it may cause corrosion....."
Max goes on to say disconnecting the fuel line while running the engine will take care of removing it.
Model plane fuel is hygroscopic meaning it will absorb moisture, but it also contains lubricant that will protect your motor while it isn't being used as long as you follow the admonition in paragraph #3.
After a flying session, I do put a few drops of 3-in-one oil in the cylinder, but according to Max this isn't necessary.
So we come to the questions is after run oil really necessary? The answer is absolutely not due to a residue of lubricant from the fuel being left behind, and if you lay your engine up, you still don't need it. Suppose after a flying session, you left your engine wet. In this case, would it prevent rust? It wouldn't do any good, since it's the properties of the fuel that causes rust.
The model plane industry is like any other (autos would be a good example) with a lot of enterprising individuals devising (or scheming) of ways to part you of your dollars. I notice that a two ounces of after run oil on the Tower web site cost $2.29. This would make it the most expensive oil on the face of the earth. In fact, more costly than a fine vintage wine which would do more to preserve my frame of mind than any attention to the OS!
After run oil is like additives for automobile engines, the reasons for buying are more rooted in human psychology than any benefit for the engine. They make the consumer feel better about himself. I suppose that some sort of catharsis takes place even if he smokes, eats high-fat food, and doesn't exercise.
Incidentally, paragraph #6 says:
"Avoid unnecessary dismantling of your engine"
Ciao,
Mr Akimoto
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Inline..........................

Sending a manufacturer an engine full of dirt will VOID the warranty. How many times have you sent in an engine full of dirt and actually received a new or repaired one mailed to you? Read the fine print on the warranty slip my friend.

If you do this, and hear any "strange sounds" your already FUBAR as the bearing surfaces, crank surface and/or piston and sleeve will already be etched by whatever dirt is still in the engine.
The proper process for checking an engine after you've plowed into the ground or lost an air filter after a huge air (for land vehix) is as follows:
1. Remove the engine from the vehicle. 2. Clean off any external dirt with a brush or an aerosolized cleanser. 3. Remove cylinder head and inspect combustion chamber for debris. I usually pop the sleeve out and check the walls for etching. 4. Remove the backplate and check for debris. 5. Clean thoroughly using kerosene, denatured alcohol, yadda yadda........... 6. Lubricate internal parts with Marvel Mystery Oil or Dexron/Mercon ATF 7. Reassemble. 8. Lite er' up!
Your "advice" is downright incorrect. On an airplane engine, we're talking about a total of 8 screws and 10 minutes to do the above procedure which could save a motor from premature wear and failure. On a land vehicle add an additional 4 screws and 2 minutes for the pull-start or rotostart.
Following your procedure could damage an engine that could potentially be saved. Sending in an engine with scratched crank and bearing surfaces and a scratched piston and sleeve tells the manufacturer that dirt has found it's way into the engine and automatically voids your warranty.
Regarding after-run oils as "hokum" (especially Marvel Mystery Oil) this is just downright wrong. I have been rebuilding 1:1 scale gasoline engines for years and years and guess what the preferred assembley lube is amongst engine rebuilders? Marvel Mystery oil. Why? It's cheap, it lubes well, and most importantly it's compressible, burns clean and leaves no residue as it burns off. Oiling an engine after each use may not be necessary in all climates and for all users, but it can't hurt and is cheap insurance.
Doc
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Doc:
You obviously have a lot of time on your hands and nothing to do with it. BTW, OS often makes minor engine repairs within the warranty period even though the problem may have been caused by the owner. I know quite a bit about this company since my family has had close ties with it over the years.
Mr Akimoto
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Yup, that's right, I have nothing better to do than dissasemble my nitro motors just for the heck of it..................
Here's a question, you lunch the landing and get dirt in the carb. You yank the motor and mail it to OS to pay them to clean it for you. How long until you get it back and are up in the air again (at least 5 days assuming 2 days transit either way and same day turn around in the repair shop)? How much does it cost?
My way of dealing with the problem costs zero dollars and will have you back in the air within an hour.
Doc
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"Doc" wrote:

Actually, I understand that OS is good about this. But you missunderstand, cleaning dirt out of the engine is not a warranty issue, there will be a charge for it. But if they do it the warranty is still good for the rest of the term, if you take the engine apart the warranty is void.

So you recommend taking the engine apart yourself and viod the warranty? That may be OK for yourself, but what about the neophyte who has trouble remembering if you loosen a screw by turning counterclockwise?
MMO is mostly solvent and not recommended for storage because the solvent may dry out and leave a stiff stickey residue. ATF is probably the best long term storage oil. When I worked at Sears one summer working on lawn moweres they simply used the same two stroke oil that you would mix in the gas, cheap and lubed a lot better than the much thinner MMO.
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Anyone who is that ignorant per way of general mechanical skills has no place in the nitro rc hobby environment IMO.

I wasn't talking about using MMO for long-term storage, I was talking about using it as an after-run oil or re-assembley lube, in which case the high solvent content is quite desirable per way of keeping the engines' internals gunk-free.
Doc
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"Doc" wrote: <snip>

I agree that sometimes it's necessary to do some amount of engine tear down, but I disagree with the order, or even need for, some of the steps in your list. As for your assertion that people who can't disassemble an engine shouldn't be in the hobby, hogwash! :) For many people, the hobby is about flying, not building planes, tearing down engines, etc.
The cylinder head does not need to be removed so early. I have seen people mess up reassembly of the head and liner, so it's best to not do this unless necessary. It's quite simple to flush out the combustion chamber without removing the head, liner, etc. I would move your step 3 lower and only do it if there are signs of a significant amount of dirt in the cylinder, perhaps because the muffler broke off and dirt got in through the exhaust port. If dirt got all the way to the cylinder through the intake, most likely the engine's got big problems, that dirt probably did big damage along the way.
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