Thats what I was thinking. And the worst part is Boat fuel is 30%+ nitro. Oooofda.

Unless you are prepared to sacrifice an engine on the alter of curiosity It would be safer to try the stainless option. When ceramics fail they do it suddenly and frequently cause catastrophic engine damage.

Steel bearings, including stainless, will give plenty of warning if you check regularly for roughness of the crankshaft.

The biggest killer of glow engine bearings is poor storage, allowing rust to do the damage.

All that rust is what is left of the bearing retainer!! That is a prime example of what happens when you dont flush your mill out after the last run of the day or even worse if the motor inhales a dose of water, which looks to be the cause here...

I figured it was from the bearing. It was the only thing in the engine that was bad. Cyl showed some wear but compression was decent. It will be replaced any-way along with the piston and rod. So, other than after run oil, what would be the end-of-the-day procedure to follow. I know it had a few "dunks" and may have ingested water but I would pull the plug and run some fuel thru it. Followed up by a dry run, you know a slow mid-range run down the river where it is less likely to suck any more water. I always pull the pipe and make sure it is clean and dry. I would like to figure out how to get the intake to where it isn't so low and apt to get water but haven't figured that yet. This thing had set for quite a while befor I got it. I probably put three or four good run days on it befor I pulled it down and found that mess. As good as this boat runs I don't mind at all to take the time to maintain it like I should and would if I just knew what it was that I was not doing. I don't run the high nitro fuel by the way. So far I have only ran 15%nitro and 18% oil in it. I did get some 60% and some 40% from the friend that gave me the boat but I haven't seen the need for it. This thing will move out with the 15% and I don't race. There isn't any-one here to race with. Just me and my son takeing turns and grinning at each other.

No ideas on how to keep this from happening again??

Make sure you run the engine dry of fuel - pull the line off the carb, start it and give it throttle. Follow up with after run oil. Be careful, though, some of them are not kind to o-rings and seals in your carb.

Air tool oil or transmission fluid are good after run oil. The methanol left over in the crankcase is the source of corrosion as methanol is hygroscopic and will absorb moisture from the atmosphere and will cause bearing corrosion. Start and run the engine wide open throttle with the fuel line disconnected at the carburetor to remove as much as possible the methanol left over in the crankcase. After running the engine with the fuel line to the carburetor disconnected, leave the fuel line disconnected and then you squirt after run oil into the carburetor and spin with the starter for about 3 seconds, then squirt again into the carburetor and spin the starter doing it 3 times more the squirting and spinning to circulate well the after run oil into the front and rear bearings. That should coat the bearings with enough after run oil. Corrosion from methanol left over in the crankcase is a big killer of bearings. Leave the fuel line disconnected at the carburetor and plug the fuel line with a fuel dot or something handy and plug the carburetor nipple as well to prevent dirt getting into your carburetor, as you don't want any siphoning of the fuel from the fuel tank to the carburetor and down into the crankcase again. 'Nuff said. Larry.

Use castor oil, at least 30% castor to the synthetic oil. Run the engine dry at the end of the day and make sure the exhaust port is open. If you must use an afterrun oil wait an hour or so to allow any fuel to dry out., Most after run oils will not mix with the fuel and all will not mix with water. If wet fuel or water is in the engine the oil will trap the fuel or water against the metal parts.

Yes, the fuel these engines burn is the worst thing you could leave sitting inside a engine, Hydroscopic means that it absorbs water out of the air and the methanol in glow fuel is very hydroscopic.  Castor oil will do nothing to displace the water and tends to gum up if it sits too long.  I agree with the airtool oil or trans fluid.  Transmission fluid is one of the best oils we have.  What I do at the end of the day is run the engine out of fuel at idle, then give it a good squirt of WD40-  the "WD" stands for water displacing which is a good thing, then run a few drops of air tool oil or trans fluid through it and you should be good to go.

No, castor doesn't displace water, but it protects the metal surfaces from rust.

If you read about bearings for a while on RCU, you will find that the rust problem is illogical at times. Members have rust issues often when they do everything right to prevent it. Then, people like me don't do a thing and never get rust.

My take on these bearings is in my review.

http://www.rcbearings.com/16001c-12x28x7-ceramic/

I looked at Boca and RC-Bearings. Boca was $40 for the same bearing that RC sold for $11 but it had a plastic retainer. A YS has 4 bearings but I only needed the rear bearing. Both Boca and RC had sets of chrome steel. On the web sites Boca on the single bearing reported back order until you got to ceramic and RC did not list anything other than ceramic.
I wil certainly still buy from RC Bearings but by phone and not on the web site. That way I can ask for chrome steel balls and bearings with non metallic retainers.

Denis

The trash in that motor isn't rust or at least I don't think it is. I do believe it is part of the retainer from the bearing and maybe some sludge from water the motor had ingested that I didn't get out. It was put away and sat dormant for about a month then it wouldn't run. I installed the new bearings and did use the ceramics and put another cyl-piston in it. I will attempt to make sure the water gets completely out befor I store her again. I am not used to getting water out of my engines because this is my first run at boats. I usually fly and have probably 35-40 that never get after-run or ran dry. I usually de-fuel the tank and wipe em down and hang them back on the ceiling. Never had any problems with them and I got some pretty old engines on them. I guess boats require more maintenance. I would turn it up-ide down and run it to get the mess out of the crank-case but this engine really scares the mess out of me when it is ran out of the water. Turns up pretty hard and quick. How-ever, it is pretty simple to get the carb and back-plate off after a days run to see what is there.

I would not recommend this at all. Bearings have a rating system called the ABEC system. Basically a bearing with a higher number (IE 9 ) has much closer tolerances than a bearing with a rating of 1. Which bearing would you rather run in your engine??If you put a lower rated bearing in your engine there is a good chance you will damage the crankshaft to block sealing effect that is super important in our small engines,Also the bearing retainer is pretty important in some engines, for example a steel cage would be fine in an airplane engine that only turns 16k but that same steel cage(retainer) in a car or boatengine could be trouble. Most high quality carand marine bearings will use a nylon or phenolic type retainer because they can turn in excess of 30,000 rpm's. Stainless bearings are not always the better option either as stainless steel is softer than achrome plated bearing, that being said if you stay with qualitystainless bearings you should be fine.

Castor is probally one of the best oils when it comes to protecting a running engine, however it does not make a good oil for protecting a stored engine, it will end up turning into gum and creating a mess . ATF will actually stay fluid and prevent any moisture from attacking the inside of our engines. Not too mention atf is much cheaper to buy as well.

Thats true of the ABEC ratings to a point but there's no reason for our application to get out of hand.

I wouldn't use either castor or WD40 for long term storage. But, castor does provide some rust protection in any case.

The best after run and storage lube is probably something like CorrosionX.

I like Prolong SPL100

Denis

I never said to use WD 40 alone for storage, you use wd40 first to help aid in the removal of residual moisture left over from the methanol in glow fuel, then use trans fluid to protect the inside of the engine. There are many different oild out there that will work but I do know this method does work as I have been using it since the mid 80's and have never had an issue since. Trans fluid is a great choice for three reasons, 1 you can buy a quart for a couple dollars, 2 it is one of the best lubricants in the world, 3 it wont attack any of the o rings or plastic on some of the carbs and it will not attract any moisture.

That looks good too. The good thing about penetrating lubricants is that they get all inside of engines without too much effort.

http://www.corrosionx.com/corrosionx.html

WD-40 is the worst oil you could use. The solvent in it will dry out and the oil left over will harden, not soft like castor but very hard and will not easily dissolve. Yes castor congeals (notgum up), but it easily dissolves with fuel ormethanol and will even soften up. Also you don't want an oil thatdisplaceswater andas with all oils is lighter than water.That means it willfloat on top of thewaterwith the water sitting on the metal. Castor willdissolve with water to some extent andit doesn't evaporate or slide off of the metalinstead protecting it with itsvarnish. Iwill use 3 in one or motor oil for long term storage but only when sure the fuel has evaporated and there is no moisture present,but engines I have neglected to oil have survived decadesas well, protected by that castor oil.

I like the 3 in 1 oil. I use it for just about any-thing and haven't seen anything that has been around for as long, or new, that works any better. I have seen WD-40 actually make metal rust quicker and can't tell you why but have seen the proof. Other than 3 in 1 the other favorite I have is Marvel Mystery oil. Like I said before, I usually don't use any-thing in my R/C engines for after run but those two are what I use for cleaning and breaking engines free that have been sitting for a while.

Maybe ask the moderator to update thread title to "Best Engine Bearing Lubricant for Storage" ...

I use this, its 4 bucks a can, I used to use Corrosion X but it was $16.00 a can.

Again, I never did say to use WD40 all by itself, I said to use it first to help displace moisture AND THEN USE TRANS FLUID OR AIRTOOL OIL, OR MARVEL, Etc... There is alot of diferent oild that will work, I have been using WD40 and trans since the 1980's and havent had one issue so I must be doing something right, by the way why in the world would you let your motor sit to let the fuel dry out?? all that will happen is the methanol in the fuel will attract more moisture!!!

Well I ran her yesterday with the new bearings and all. Tuning was a little rough. Not knowing the initial start points on the carb and all. Got it close and ran it pretty easy untill it did something it has never done before. Right off the launch I punched it to check the hole shot and it did a complete back-flip. Well almost a complete one. I brought it back up to shore and did the whole dry it out thing and decided to call it a day. When I got it home I decided to see just how much was still in it so I pulled the carb and back plate and sure enough it still had water in it. Point being that in order for me to get all the water and mess out this is what I will do. Four screws on the backplate,don't have to remove the carb and I can see the entire crankcase rod and all, dry it out good and put in a little 3 and 1 and put it back together. I can do this with the motor installed so it really isn't that bad. As for the origional post about ceramic bearings, I love them. I have never seen a motor turn this smooth and free with absolutely no slop. If the extra labor helps keep it that way, so be it! My son says I am getting "anal" but he can't deny it is worth it to see this thing go across the river at 70!! The O.S. 81 in this one turns hard and runs in the worst conditions I can think of for a 2-stroke to run in so extra maintenance should be expected I guess.