Sport_Pilot

It's a model engine, not a car or other expensive item.  Unless it is rare it does not warrant the time and effort to take apart and clean.  99% of the time that is all it needs.    99% of the time that is all it needs.   If the bearings feel good after disolving the castor with fuel, then run it.  If it breaks, so what, buy another, or parts for it.    Now if this was likely to be bad more often than not I would say otherwise, but it is rare if castor fuel is used, and since the castor is why the balls are stuck, then it should be good.

flybyjohn

My Feedback: (2)

I am not going to argue with sports pilot, It will run 99% of the time with just loosening it up and running it. But if it does have rust in it, which many that sit for 10 years do, it will shorten the usefull life of the engine and may decrease the performance. I don't know if where you live is humid or dry, but a humid climate will promote rust more than a dry climate. I run my hobby on a limited budget with more time than money so I always take the 1.5 hours of my wasted time and clean the engine first, then I run it. If you start with a clean engine, you eliminate unknowns when it doesn't run quite right. It's realy up to you, if you like to tinker then take it apart, if you are short on time and have some extra money, just run it and if it doesn't run well, sell it on ebay and buy a new engine.

fizzwater2

My Feedback: (61)

remind me not to buy any used engines on ebay...

Sport_Pilot

You said take it apart and clean it, That would take a lot longer than 1.5 hours, especially on a four stroke..Not to mentioned many perhaps mostare not able to take it apart and put it back together. If it is a ringed engineyou will actually put more wear and tear on the engine doing this as now the ring has to reseat. You simply don't need to take it apart to clean it, several methods have been mentioned in this thread that will clean the inside of the engine. Not even the engine experts in the rags recommend taking the engine apart except to replace broken or worn parts. Jaka has memtioned pylon racing, but that is a completly different animal where the engine will likely be worn out regardless.

jessiej

I have bought dozens of engines on ebay, and been disappointed in very few. I expect to purchase quite a few more.

jess

fizzwater2

My Feedback: (61)

Me, too (well, not dozens, but some). I've gotten some really nice deals from decent sellers, like the Jett Q500 engine I got that had a brand new piston/sleeve/head in it - the seller had forgotten that he sent it back to be refreshed. But, there are those, that "if it doesn't run right, sell it on ebay".. you just have to be careful what you buy. Let the buyer beware, eh?

JollyPopper

My Feedback: (6)

The point is, guys, that if castor has been used in the engines and it has hardened over time, it has coated the bearings much like cosmoline does. That keeps moisture off the bearings, even before it hardens, preventing rust. Dissolve the castor and you might have clean bearings. If the bearings are clean and the engine turns smoothly, run it. I agree that if there is rust in the bearings they should be discarded no questions asked.

JollyPopper

My Feedback: (6)

I just had a thought. Let's say you have an engine you want to store for an extended period of time. Take the back plate off and pour melted candle wax in it until the rear bearing is covered. The wax will solidify and enclose the bearings like a glove. Now that turkey will not rust. Castor does virtually the same thing except that ten years down the road it can be dissolved simply buy immersing the bearings in fresh fuel.

flybyjohn

My Feedback: (2)

I assumed it was a 2 stroke engine in a 4 star 60 because it is a tower hobbies engine and I don't think they made 4 strokes. And yes, it only really takes about 15 minutes to totaly disassemble and reassemble a two stroke, then add in some time for cleaning and polishing, don't include the soaking time, and 1.5 hours is very liberal on the time. There are only 6 bolts in the head, 4 bolts in the backplate, throw it in the oven for 10 minutes, out will come the liner and pop the piston off the crank, the crank will push out the back of the engine, engine disassembled. A quick 10 more minutes in the oven and the bearings will fall out if you want to go that far. Soak everything and reverse order to put back together. A small four stroke is a little harder depending on how the wrist pin comes out and unless you want to dissassemble the valve train. I can say that many of the engines I have taken apart that I bought off ebay have had rusty cranks, some have not. It depends on how humid it was and how the previous owner had stored it. Rust is bad, and disassembly is easy and very effective at removing contaminates.

rcdude7

My Feedback: (264)

This is what I do also, the iron oxide (rust ) is very abrasive and by running it through the engine you can take years off the life off it. I use a toothbrush, alcohol, and a green scotchbrite pad to scrub the rust off the crankshaft. No need to get evrey spec just the stuff that will get loose into the engine as it runs.

Sport_Pilot

I would like to know how you take an engine apart in 15 minutes! Just removing the bearing takes much of the 1.5 hours for me! I have taken over an hour just removing thebearings on some installations, mostly waiting for the case to heat up.

Not to mention I have only had one engine with bad bearings, and the only bearings I have seen rust on were not installed in an engine. I have stored engines with gunked on castor for almost two decades and no rust found. Seems totally unnecessary to take the engine apart. I have had more damage from taking an engine apart and putting it back together than from rust. Ususally a broken ring. Maybe I am just incompetent and slow.

Tmore

My Feedback: (1)

Heck, Ibet Ican take a 2 stroke with locked up bearings apart in less than 15 minutes. If it takes you longer than that....you are doing it wrong!! Head, muffler, carb, backplate...gone in 60 seconds. Slide out the sleeve, pop the piston off the crankshaft...another 60 seconds. Pop it in a 350 oven for 10 minutes, crankshaft and bearings out in 30 seconds. Nothing to it. If you are having major issues then I'd say you aren't heating it up hot enough.

Sport_Pilot

Takes that long to preheat the oven. I would be afraid of messing something up doing it that fast. Yes I suppose itcan be done, but why? But even if you can. Why Bother? Congeled castor is not something that causes rust. It protects it from rust and disolves with fuel, and melts with heat. It is just completly unnessary.

If you are constantly taking an engnine apart and cleaning it, it won't last as long as an engine that is never taken apart. That is because the parts must set in and wear off the high spots each time.

flybyjohn

My Feedback: (2)

SportsPilot, I may have worded that wrong. It takes me 15 minutes to dissassemble most 2 strokes and 15 minutes to reassemble the engine. Not 15 minutes to do both. The bearings on most engines I have disassembled have not been very rusty only a few rusted to the point of not turning, but the place that grows the rust is the crank shaft. It will grow around the counter weight and in the intake bore. I like to get all this loose stuff out of the engine so it does not have to run through the engine cylinder.

I use the oven or a propane torch to heat the case. If using the oven, preheat to 350 deg, put engine case in oven let set 10 minutes take out of oven and tap back of case on cutting board three times and the main bearing will fall out 85% of the time. If it is still warm enough, stick a small dowel in from the back that will catch the front bearing and push it right out. When putting the bearings back in, heat case same way and new bearings will drop right in the holes. I put the front bearing in first and then use the crank to put the rear bearing in from the back. That helps align it. You should not have to press or tap the bearing, if you have to start tapping, it is not going in straight or the case is not warm enough. Sometimes I will tap the outer ring of the bearing with a socket to make sure it is seated after it is in the bottom of the hole but it usually is. If you want, you can put the bearings in the freezer for 30 minutes prior and it will even be easier. Bearings are usually interference fit in the case, or almost size for size so by heating case and cooling bearings the clearance really becomes larger. The aluminum case will expand quicker than the steel so by putting it in the oven for ten minutes the case will grow bigger than the bearings and they should drop out.

Most engines today are ringless and that simplifies things a bit. I think the tower engines were abc. But if there is a ring, if it looks good, and there is not any crud on it then it does not have to come off the piston. A quick warm bath in antifreeze will soften the crud and it will wipe off. I have not broken a ring taking it off or putting it on yet (knock on wood) and have reused all the rings of the engines I have cleaned thus far, mostly because the engines with rings I own, have been discontinued and stock rings were unavailable.

SportsPilot, I don't want to be a sore on your back side, just letting the forum know what I do with old frozen up engines. I have just started up engines that have sat for over 10 years in the past but after seeing what some engines look like inside now I perfer to clean them up first, I usually end up doing it eventually anyway. I feel comfortable with taking things apart and fixing them and it is up to the questionee to decide how comfortable he is and figure out what he would like to do with the information he gets from people on this forum.

Tmore

My Feedback: (1)

I guess I assumed you could be doing other things while the oven pre-heated...I don't tend to sit and watch mine heat up. For me it's just a piece of mind thing. I'd rather spend $15 on new bearings than have something fail later. If you have had success not replacing bearings...cool. I've had success replacing mine. I just got back into the hobby after a 4 year break. Replaced the bearings on my Tower 46 (10 years old'ish) and it runs like a top. I've probably replaced bearings in 4-5 engines over my r/c career (25 years or so) and never had to retire one of those engines due to lack of performance, only from lack of "pilot performance".

rcdude7

My Feedback: (264)

I have always been a mecanical minded person and changing bearings has been a easy task for me, I have done over 20 of my engines easily. I started out using a propane torch, like for sweating copper plumbing (risky), then the oven method (safe but time consuming), and now I just use a monokote heat gun every time (best), it really is the safest, quickest way to go. The most troublesome change I have done is a saito 150, the tight tolerances caused me to have to draw the bearing in with a puller while maintaining the hot case with the gun, it went in fine just a little more work that I have had with my OS and enya engines.

My final step, when the engine is back together, is to mount a prop and then heat the lower part of the engine again to allow the bearings to locate themselves in the bores and eliminate any binding that may exist, however slight, then allow the engine to cool slowly.

Sport_Pilot

I too am mechanical minded, I have a degree in it.  And spending time pulling the engine apart is a waste of time even if spending one second because you can clean it without pulling it apart and you are inceasing wear to the engine.  Now if you are racing then the rigor's or racing do warrant close inspection, but we are not talking about racing here.

flybyjohn

My Feedback: (2)

I wonder if Crossbow1 ever got the engine freed up. He hasn't replied to any posts yet. Probably just sitting back watching the debates over taking apart and cleaning or leaving together and cleaning. I guess for my last post in this thread, I would at the very least take off the backplate, muffler and head and inspect things before running an unknown engine that does not turn over.

Sport_Pilot

Iwould agree with that. Although for many of my engines that would mean taking them out of the plane, and Iwon't even do that.

rcdude7

My Feedback: (264)

It only takes a few minutes to field strip a .61 size O.S.

At the moment I have a 2.0 litre escort engine I am rebuilding because a intake valve seat shattered while it was being driven, what a mess that is.

JollyPopper

My Feedback: (6)

I agree that removing the head and the back plate on a two stroke engine takes only seconds. However, I have run into engines in which the liner won't just "slide out" even after heating. I had one just recently that would move up and down just slightly, maybe 1/16" as the piston reached the pinch point but it WOULD NOT come up higher. How do you guys who dismantle and engine in 15 minutes remove a liner that is free in the cylinder bore but does not want to go higher than 1/16" above the cylinder. By the way, this liner was stuck tight in the cylinder bore until I heated it with a heat gun. I watched the goo sizzle up between the liner and the case for a few minutes and then the liner would move slightly but not past 1/16" or so. I assume it was catching on some crud around the exhaust port.

Tmore

My Feedback: (1)

If the liner is hard to get out, Iwould say heat it up more...maybe crank the oven up to 450 or 500. Iusually take a wooden stick and go up through the back of the crankcase and push up on the bottom of the sleeve.

1QwkSport2.5r

A plastic ziptie through the exhaust port works great - use the crank and piston to push the liner up. My Aero engines all come apart pretty well, though my car engines are a good bit tighter. Most often the ziptie trick works. Some of the more stubborn ones get a quick heat treatment of the torch though I havent found the need for this in quite awhile.

flybyjohn

My Feedback: (2)

I had a liner that actually needed to be pulled with a puller I made. I think it was a tiger shark 52 engine. The liner had a recessed grove on the outside of the liner up by the lip and when it was torqued into the case with the head, the aluminum of the case must have deformed slightly and squished into this ressessed grove. the groove was about 1/16" so mine did the same thing. It would spin in the case and lift up and down in the case by about 1/16" but would not pull out. I had to fashion a puller out of aluminum to pull the liner, It was tight the whole way out. Before reassembly I chamfered the top of case so that the liner would not get stuck the next time.

This was not a 15 minute engine.

JollyPopper

My Feedback: (6)

I had that sucker somehere around 500 degrees and the liner still would not come up. I could not use the crank to move the piston up and down because the whole reason I was doing this was due to the fact that the crank pin had broken off the crank, thus moving the piston with the crank was not possible. I was pushing it up and down with my fingers through the back plate opening.

This reminds me of an interesting bit of info that many of you may already know but I did not. The engine I was working with was an Evo .46. I posted an ad on RCG looking for a used crank for said engine and got an immediate response from a gentleman in Hot Springs, Ar. saying he had the crank, piston/liner/rod assembly from an OS .46FX and that it would fit the Evo. I had him send the pieces, and sure enough, parts were identical. So now my Evo .46 is running very happily with an OS crankshaft and I still have the piston/liner/rod assembly for the OS engine if anyone needs it. They will also fit an Evo .46 and who knows how many othe engines.