Engine, back plate troubles
 

Hello, its been a long time since flown one of my RC planes and Iwant to get back in to it, but I'm stuck with an engine/prop problem.

Ihave a p-51 mustang that Ihave taken out of storage. My issue is, when the back plate is on and the prop installed with bolt and washer, Ican't spin it. It's extremely stiff andif Ilosen it a little it will turn but then after a few rotations it just becomes to loose and wobbles. When nothing is on the engine, it spins, but it does seem stiffer then it should be but it has been so long I'm not sure how easy it should turn. Iknow that it turns easy, then hits a point where it gets a little stiff and if you get past that point it turns easy again. The point that gets stiff just seems to stiff. So Iguess I am wondering why is it so hard to rotate, there is no way it will start being this stiff, am Imissing a piece?

I have a picture attached maybe you can tell if it is installed wrong? Any help I'm thankful for, Ilive in an area where we have no hobby shops, no local help.</p>

RE: Engine, back plate troubles
 

There is supposed to be a thin thrust washer between the body and the drive washer.
Is it there?

KW_Counter

RE: Engine, back plate troubles
 

Perhaps if you could remove the prop and the parts behind them and a post a pic of what came off. we could see what is missing. Also exactly which engine is that? I'm guessing one of the FX series.

Here is a link to the parts diagrams that will show what should be in there.

http://www.osengines.com/parts/exploded-views.html

My other thought is that the front bearing may be gummed up and giving you additional resistance when everything is tight.

RE: Engine, back plate troubles
 

"I know that it turns easy, then hits a point where it gets a little stiff and if you get past that point it turns easy again."

That sounds like your compression. If you stored the engine with a good treatment of after run oil it may have some in the cylinder causing it to hydrolock at top dead center. Try removing the glow plug and turning it over. A good engine will still give you a little bit of resistance as the piston gets near the top but not nearly as much as it will with a plug installed. If the engine feels draggy or gummy all the way around, it probably needs a soak in denatured alcohol or old glow fuel for a few days to loosen everything up.

RE: Engine, back plate troubles
 

If it was running well when you stored it then it isn't the thrust washer missing unless you have removed it during a clean up. Did you use the plastic spinner with it before you stored it? Jester may be correct about oil in the top end too. A good cleaning is always a good idea when using an engine that has been stored for a while. What you describe sounds like the thrust washer to me though?

RE: Engine, back plate troubles
 

Thank you everyone for responding! Finally founda place where people want to help out. Hehe sorry I'm excited about getting back in to this.

Okay so I'm at work but when Iget home Iwill take another picture of the engine and seperate the parts on the stem so that you can all see the parts Ihave and the order ihave placed them. Ido have a washer on it, but I'm not sure if it's the "thrust" washer and which is a thrust washer. The engine was storedasthe picture shows, Ionly took off the nose cap for picture. I am pretty sure Ihave never started it, it was installed brand new from the box, but then just sat in a cob web filled basement for 10 or more years.

Iwill try removing the glow plug andIf it moves easier then what do Ido next? For cleaning the engine, all Ihave to do is soak it in achohal? What is glow fuel, is that just fuel that Iuse to run the plane? The fuel Ihave is very old, not opened, but probably10 years old, does the fuel expire? I contacted O.S they said Icould ship it to them and they could fix it but I'm not sure if it's cost efficient, if Ican be instructed how to repair it I'd rather save the money and time. They said it could be the bearring which I watched a video and that looked like a lot of work to get to.

Sorry for all the questions and crossman, Ido not know what kind of engine it is, it's a O.S but that is all Iknow, Idon't see a model written on the engine itself and Idon't have the box or anything else for it now.

I wish i could post a video, I think that would help. Thanks again guys I'll try to give you as much info as possible but I am new and donot know what all the parts are called.

RE: Engine, back plate troubles
 

I meant to say drive washer, not thrust washer again.

RE: Engine, back plate troubles
 

Igmac, there will be a lot of people glad to help you, but if you don't know what glow fuel is, that shows you are absolutely brand new at this.

Anyone that new is going to need A LOT OF HELP and typing back and forth is about the worst way for you to succeed. In fact, there is an excellent probability there is nothing wrong with your engine at all. It might not even be gummed up if you haven't run it. BTW, don't pull the glow plug yet. You say "Turns easy, gets stiff, turns easy again." That's what all engines like yours do. The stiff is probably compression.

To see what size the engine is look on the other side of the cylinder. Look under the muffler, just above the mounting lug. There should be something like "61" or such.

Some engines have a thin, flat steel washer fitted over the crankshaft, just behind the drive washer. The drive washer is just behind what you're calling the backplate, which is just behind the prop etc.

See how long this is taking.......... The best thing you can do is find some modelers around you and talk to them. Talking will get you farther ahead in one minute than we can get you with days of typing.

But keep asking until you find someone. Some will try to help best they can as long as you want.

RE: Engine, back plate troubles
 

A brand new engine uses what we call the squish of the top of the piston as it comes up to the compression and in all brand new engines you will have a spot towards the top of the stroke that starts getting tighter and tighter. That's normal. I'm guessing right along with the rock you have nothing wrong with the engine at all. I also agree with him 100% that it sounds like your brand new to the hobby from the terms you are using. Follow the rocks advise and take your plane to a club and ask someone in the know to lend you a hand.
If your fuel is in a can or the jug is out of the sun light it's probably still good if it has never been opened. Take it with you to the club but the person that is helping you will probably just give you a tank full to get the engine running then try/test the fuel you have. It will either work or not work. Not a lot of gray area there. If the engine runs on the new fuel and not with yours then it old fuel makes a fantastic weed killer. That's not a joke.
Find someone to help you hands on so they can see, hear and feel your engine.

RE: Engine, back plate troubles
 

You say "it's been a long time since you have flown your planes".

Then you ask "what is glow fuel"?

And you say "the engine has never been started"?

With all due respect. How much experience do you have. The plane you are dealing with is not for a beginner. Take the others advice and get with someone that can help.

RE: Engine, back plate troubles
 

Yes I did ask that, so what is glow fuel? When I was flying planes long ago, I remember only having one type of fuel which happend to be pink color, and that was the only fuel I used.

I started with an Eagle 2, it was a kit. Yes that is a beginner plane, it was easy to fly and that is the only one I ever did fly. However I was a natural and I've always had good eye handcoordination. I'm not worried about my abilities as a pilot, just as the mechanic.

Alright there has been a lot of information here, still at work so I have not been able to try anything.When I get home I will:

1. Take a picture of engine so that it's clear all the parts that I have (washers, etc) and also find a size if possible

2. It's November and i'm in VT so I won't be able to meet anyone on the field but I believe there is a website for an rc club here. I will email the admin and ask for help from it's members and maybe I can get one to come over or I go to them.

3. I will check out the link to the engines, I've printed out the one that I think is mine, but probably wrong.</p>

4. I don't know what else yet, I was going to remove glow plug...but somebody said not to do that if it's new which is my best guess that has never been used, Imay have taken it off my Eagle 2 plane. If Ican't think of something I can take apart the engine just enough to check how clean or dirty it is, if it looks good inside then I'll put it back together.

5. I will buy a new plane, new engine, reciever, servos and anything else ineed. Iam looking to do this either way because I want to get another eagle and put pontoons on it so i can land in the snow and lake champlain. Until then though Iwould like to get the mustang running.


BTW
I know that there is supposed to be some resistance when rotating the crankshaft (now I can use the correct terms for engine) but it I strongly believe it's too much. I mean it takes much more force then I remember and does not bounce back, and like I said with with all the peices on it will not rotate at all.</p>

5. </p>

RE: Engine, back plate troubles
 

Engine is a O.S. 46FX model.<div></div><div>I wrote an email to the RC club here. I found another engine, a smaller one and the crankshaft moves around much easier on it, which still leads me to believe something isn't right on the one I'm trying to use.</div><div></div><div>I was hoping this picture would help see the parts I have but now that I look at it, it's not that great. I am looking at the parts on the page that I printed out with the engine parts, i have propeller nut, propeller washer, drive hub, however I can't tell if there is a thrust washer which is the next peace. There is something behind the drive hub that is silver that is washer like but not sure if thats it, or thats the crankshaft ball bearing. Guess I'll have to take it apart to find that out.</div>

RE: Engine, back plate troubles
 

Your picture shows the drive washer displaced much too far forward. It looks like the front of the crankshaft has a flat cut in it that the drive washer would mate to. It's how the shaft 'grips' the drive washer on some engines. A properly assembled engine would not have any crankshaft exposed. I'm assuming you loosened the prop nut sufficiently to allow showing off whatever might be between the rear of the drive washer and the front of the engine.

However, if you've got the prop nut tightened up and figure the engine should run that way, that isn't how it works.

A question.... your hoses and connections.... any reasons for how they're arranged?

RE: Engine, back plate troubles
 

Page 24 of this manual shows an exploded view: http://manuals.hobbico.com/hca/hcaa17-engine-manual.pdf

part #10 on that page shows the washer a few have mentioned. It's sometimes lost when we do things that allow us to remove the drive washer. If it's not there, the engine turns over without problems. If gone and we put pressure on the prop or spinner the rear of the drive washer grinds against the nose of the crankcase.

Hope this helps

RE: Engine, back plate troubles
 

Yeah I've loosend it so that each part could be seen better and be more seperated. Usually when the propeller nut tight, the shaft does protude from the washer some. I don't know what is with the tubing but I know it's wrong and I know how to set it correctly, it's just how it was when I pulled it from storage.

I managed to find a 45 page manual on my engine, I have not read it yet but it looks like it could have some good info in there. Still stumped about how stiff everything is and why it gets harder to turn the tighter I make the prop bolt.<br type="_moz" />

RE: Engine, back plate troubles
 

There is no "thrust washer" No. 10 item, between the drive hub and crankshaft ball bearing. Also it's the engine is pretty cold, which I've now read makes it harder to turn. I needhttp://www.advantagehobby.com/46467/OSM46120000/and just maybe then I can start to make some progress. I opened the engine just a little, the back cover plate and it's very clean in there. I hope they sell this at local hardware stores, thanks guys.

RE: Engine, back plate troubles
 

OK, that missing washer spaces the drive washer away from the nose of the crankcase. Without the washer in between, the drive washer will come into contact with the front of the case when the prop is tightened up. Your very first picture actually shows the drive washer apparently touching the front of the crankcase. They don't work too well when that happens.

RE: Engine, back plate troubles
 

Part #10, the thrust washer is very thin and not something you would usually locate in a hardware store. Phone a hobby shop and ask if they have the thrust washer for the OS .46 FX in stock or order one yourself. Good luck finding someone to help you. Even more good luck flying the P-51, they are nice planes.

RE: Engine, back plate troubles
 

New engines have some oil in them to prevent corrosion, so that's likely what's causing it to be hard to turn. I didn't understand that this was a new engine though, so I'm going to add that you shouldn't be turning over through the compression while cold like that before it breaks in. The top is intentionally tight so that when the engine is first run up to operating temperature the liner will size itself to the piston and make a perfect seal. The friction and pressure are immense when turning a new engine over by hand, so ideally you should leave it alone until you are ready to start it.

RE: Engine, back plate troubles
 

I'd rather have a kit, easier to make repairs on balsa wood.  This was a present so I'm not complaining, my next plane I would like to build, and save the money.

RE: Engine, back plate troubles
 

I have a brand new OS 46 that has never even been opened yet... I can open this box up and take the prop nut off and describe to you what comes off the shaft in what order...That way at least you will know that you have it assembled correctly....
.....Okay first off is the prop nut then the prop washer...The prop washer is black and is a little bit thicker at the inside edge....Next is the drive...It is aluminum coloured and about 1/4 " thick..It has grooves in it to grip the prop on its face ... Next is a very thin but VERY important washer that goes between the housing and the drive......Everything must be in its proper place...The prop would go between the prop washer and the drive of course but its not in the box.....If you need me to I can take a picture.....I rember trying to assemble one without that little black shim that goes between the housing and the drive once and every time I tightened it up it became harder and harder to turn...

RE: Engine, back plate troubles
 

Just for the record in all three photos the fuel line plumbing is wrong you have bypassed the main needle valve and it cannot run like that.

If the #10 washer shows up missing and this engine was new ten years ago and not run. Then the washer was simply lost back then when the drive washer feel off at some point and you replaced the drive washer without the #10 washer. This is very, very common with many OS engines.

Get an experianced flyer to prepare that airplane for flight and request him to fly it for trimming and adjustment. This can take more than one flight. Only then request a buddy chord flight and many mentors/instructors will decline as that is not a suitible airplane for you to learn on, natural or otherwise. Smart money is to hang that one up for later and get a modern proper trainer.

The Fortysix FX is an excellent engine and would serve well installed in most modern trainers. That fifty one is an older Arf construction that consists of a thin molded foam shell that is mounted over a plywood crutch and bulkheads. The foam has a printed paper laminate that provides the markings. Great planes sold the p-51 and a FW 190 fifteen years ago and while they fly OK they are virtually unrepairable and typically do not last long.

John

RE: Engine, back plate troubles
 

Bikerbc, it sounds like besides the thrust washer Ido have everything else Ineed. Ihave ordered that part, although shipping cost more then the washer. Thank you though, that list was helpful. Iwatched on you tube that if you stick the engine in the oven around 250 for not very long just so it gets warm it may start easier.

Johnbuckner, Iam aware the tubing is wrong, I don't know why it's like that I just did not fix it before the picture.

As nice as it would be to get someone to help me trim if my attempts to find someone continues to fail I'm going to try and do everything myself. I can read how to break in the engine, it's in the engines manual. Also once Ibalance the plane,then just looking at the alerons, rudder and elevator (those maybe the wrong terms)to make sure they are flat with the rest of tail/wing then that should be good enough to take off, and Ican trim it myself. I am good at flying these, and if Ido crash it well I'll deal with my poor choice. Ido plan on building another plane from kit but that will take a while and I want to get this engine idling.

Do you guys think an O.S 40LA engine will be enough power to lift this plane off? That is my other engine Ifound. Also will cold air stall an engine, what if Iwere to fly it in 50 degree weather.

</p>

RE: Engine, back plate troubles
 

Cold air won't stall an engine.

If the engine has a needle setting from a day when it was warmer and/or lower pressure, the needle setting will be leaner. Going from hot to cold, expect to richen the needle. Going from cold to hot, expect to lean the needle.

If the engine is new, the recommended needle setting for starting will work. When you follow the mfg's instructions, no matter what the temps, you'll wind up with an appropriate needle setting.

RE: Engine, back plate troubles
 

The 40LA should be able to fly any of the planes you've mentioned so far.


Getting the OS thrust washer is the appropriate thing to do. It is dimensioned properly for the purpose OS intended. The outer diameter matters, as do the inner diameter of the hole in the sucker, and the thickness and uniformity of the thickness matters.