I opened my OS .46 FX and didn't know if I was looking at something good or bad . Feel free to leave your comments and suggestions . Thank you.

The top of the piston looks a little burnt but not real bad. From the pics its hard to tell the condition of the liner.
Whats the compression like? How does it run? These are a better indication of the condition of the motor.

The engine is fairly new about 5 or 6 months old. It runs very good . I can hand start this engine every time on the first flip . The sleeve is smooth , no scratches or blemishes.

The one thing I'm worried about are 1- there is no more tightness when cylinder is DTC. Should I be concerned or should I just continue to fly? Thanks.

Edit , no low speed needle

I must admit I do not understand the problem. You say it starts easily, runs well and has required no low speed adjustment. What else do you wish it to do?

I also fail to understand the need for disassembly of a perfectly functioning, broken in engine as it is unlikely that all the microscopic wear patterns will be exactly matched upon reassembly.

Obviously I am missing something. Please explain.

jess

EDIT: Fixed HTML coding. wr.

jessiej ,WILL YOU GET OFF OF MY B A C K DUDE ! Why is it every time I make a post you chime in with nothing to say but blaa blaa blaa. ?

The reason I disassemble the engine since you need to KNOW ! is because I haven't flown my trainer in some time now . So I brought the trainer in because I converted it to a flat wing and decided to also balance the plane since I have never have done so and at the same FLIPPING TIME I wanted to check the engine for crying OUT LOUD ! Now if me doing this rattles your cage the I apologize but please stay with in the scope of the post sometimes and also learn how to use thE QUOTE BUTTON . [>:]

Fiend, I can't imagine what upset you so, but rest assured, I shall reply to no more of your posts. Have a good time and try to chill out just a bit, such stress can't be good for you.

jess

What pissed me off is the post clearly states I was wandering if there was any thing wrong with the engine. If I made a post about 'should I disassemble my engine it's running well', I can clearly understand your answer to such a post. So the choice is yours whether you answer any of my post or not , but it seems this is becoming a normal reaction of yours toward me for some lame reason and all i can do is retaliate the way I did. There have been many post about people disassembling their engines and not once have you commented on why it was done. There are post I find to be very silly and I just don't answer them and move on. I think you need to reevaluate your reasons for answering threads and we all can just get along. [8D]

P.S. I am as calm as a BUD ICE drinker can be at this time.

What Jessie is trying to tell you is that you shouldn't have taken your engine apart. There was nothing wrong with it before you took it apart. Now, Who knows?

The lack of a pinch at the top is not detrimental to the engine as long as it still has good compression.

Enjoy,

Jim

LOL I didn.t take my OS.40 apart for almost a year only to find I was running it to rich and also found the linning was pealing and it ran fine. So I'm not sure what the big deal is but whats done is done lets move on.

Oh look at this...I've used the QUOTE button
I'm not quite sure what you want us to tell you. The photos are way too fuzzy to make out any details other than the rubbish on top of the piston. Why pull an engine to pieces when you have no idea what you should be looking for? All you can say for certain is yep, it's got a piston...oh lookee, and a liner too...

Your first post did not clearly state you were wondering if there was anything wrong with the engine. For all we knew you just pulled it to bits for fun then didn't have a clue what you were looking at. And probably not the slightest clue how to put it back together again properly either.

Now get over your snot nosed attitude and try to realise that some people have been genuinely trying to help.

[sm=sleeping.gif] [sm=redface.gif] [sm=sleeping.gif] [sm=thumbdown.gif] [sm=confused.gif]

[sm=idea.gif] Oh I forgot this is forum for receiving help [sm=idea.gif]

Okay, here's my suggestion...never open up a perfectly good running engine.

Now for my comments...As far as jessiej, he was just stating facts, I don't see why you had to unload on him as you did. Based on your attitude in this post, maybe the next time you genuinely need help, everybody will tell you to **** off.

Having a good attitude and a genuine desire to learn will take you a lot farther than being a jerk.

[sm=sleeping.gif]

[sm=sleeping.gif] [sm=redface.gif] [sm=sleeping.gif]

[sm=lol.gif] I guess this is going to turn into a peanut gallery for some unseen reason , OH yea I never particularly ask anyone of you for help , and thank god I didn't because I wouldn't have gotten it anyway. You are the type of guys that need to vent some where so here is where you choose to do it . An easy solution for me asking a question about my engine is to say nothing is wrong reassemble the darn thing. Then if you feel it was silly for me to open it then give your reason behind your feelings . Not one of you have done this so thanks for trying to help me but the engine is back together and I'm going to fly

This statement is why people are confused, mind you this is my opinion, your description describes my 40fx, its running 13200 with a 10-6, its perfect. Your asking for peoples opinions on their experiences, if you dont like them then you shouldnt ask. I dont always like they way people answer, but everyone is different... Have a good day.

I am going to agree with RC-FIEND here. Folks come here to this site to learn about our hobby. People learn how internal combustion engines work by taking them apart! Anyone here with any time under their belt probably gained their experience by experimenting and doing just that.
RC-FIEND, You have done no harm by opening the engine to inspect it. In the future (and you may have already done this) prior to removing the sleeve from the crankcase scribe a small mark so that the cylinder can be replaced back in the same exact position. Also make note of how the piston and rod are removed and make sure you replace it the same exact way they came out.
To answer your original question, the dark discoloration is normal on the top of the piston, thats where detonation takes place. If a significant amount of carbon builds up here, it should be cleaned off, but based on what I can see with the photo yours is fine.
If you want to get some real good reference books on current Glo Engines try and get hold of one of Harry Higleys engine guides or the one from Peter Chin through Model Airplane News. Both have a wealth of information that I still refer to once and a while. Both books will take you through a complete break down and rebuild or reassembly.
If you need any other help, feel free to PM me, or Hobbsy when he is here. He is a very nice gentleman who has considerable experience with model engines.

Oh look....I used the quote button as well.

It's hard to tell from the glare in the picture #2, but it looks kinda like the
liner is starting to peel. [X(]

FBD. []

I thought so too, Woody, and I thought they were rather mundane, non controversial facts at that. If I had ever imagined that such simple statements could cause anyone to become so excited, upset and overwrought, I'd never have tried to help.

Now I have had one of them learning experiences. I sure wouldn't want to be responsible for causing someone to have a stroke!

CCRC1, Thanks for looking past the negative remarks in this thread , and I appreciated you offering to help me the next time I need to know something.

To sum things up a little , I flew my newly converted flat winged trainer today with the OS .46 FX engine and it flew perfectly . I hand started it on the first flip and it just didn't want to stop . The only thing I noticed is when I leaned the high speed needle out a little, I continued to see white smoke. So going off of the 2 stroke note I moved it back to the four stroke note just before changing again to the 2 stroke note as the manual recommends. I definitely need a tachometer to check the RPMs.

The one little thing that disturbed me was although the trainer wing was flat it still had it's slow flight characteristics. [&o] But I need to practice turning and not having the plane re-correct itself.


P.S. I was thinking on the way to the field , most say don't check the engine if it seems to be running ok.
Well I hope you guys don't take this attitude with your health. The point is it really can't hurt just to
check anything.

Come on, what do you expect, he's from NJ[:'(][>:] The bad half of the state

Spoken like a true beach BUM ! [sm=drowning.gif]

Fiend, nobody that replied here was trying to give you any grief. Here's why we told you not to disassemble an engine needlessly: On a ringed engine, the ring seats in relation to it's orientation in the cylinder sleeve. If the ring is free to rotate, as it is in some Super Tigres, Fox engines, and others, and you then pull the piston from the cylinder, unless you install a new ring when you reassemble the engine, you are going to have a loss of compression.

On an ABC or ABN engine such as your FX, it's even more critical not to disturb the piston/sleeve wear pattern, for the same reasons mentioned above. The piston and cylinder "wear" into adjustment with one another, if you move that relationship, the engine will have high and low spots in the cylinder/piston fit, leading to friction and blow-by.

Happy Landings!

I'm attempting to combine quotes from two posts, maybe it will work as intended.


What does "no low speed needle" mean? Since a follow-up post says it is back together, and running fine, I'm guessing it doesn't mean the low speed needle is missing. I don't remember if you stated whether you have a tach. If you do, monitoring the peak RPM occasionally will tell you if you're losing a lot of compression. I am a "don't fix it if it's not broken" person when it comes to mechanical things.


From what I've been told, the main benefits to taking out the dihedral on a trainer wing are easier inverted flight and easier takeoff/landing in a crosswind. Since the airfoil itself isn't changed, you still get the same lift and the same amount of aerodynamic drag, it makes sense that most flight characteristics would stay about the same.

Happy Landings!

All I took apart is the cylinder head ,and took out the sleeve. Now having said that I will continue to do so every 25th or so flights. The reason, will be to check if there is any damage. I refuse to wait until I put this engine into an expensive plane only to dead stick to a crash because the top of the piston is so burnt it doesn't perform when needed.

I get your drift , the engine comes with a notch in the sleeve and a pin on the case. I don't' think I will put it back the wrong way.

In the beginning I was going to post , I never touched the low speed or mixture control valve , Then I edited the post and removed the question. NOW I just read there is a low speed needle which brings me back to the question I deleted . Should I leave it set the way it is or should I play with it to obtain better idling. I guess I won't know until I buy a tachometer.

In all seriousness, it will take a lot (5 or 6 gallons of fuel) before a significant amount of carbon will build up on top of the piston to the point where it will become an issue. If you want to periodically pull off the head to inspect inside, thats O.K. There really is no need to pull the cylinder out, just cycle the piston down and you can inspect the cylinder lining leaving everything intact.
Run good quality fuel with decent lubricant. Use after run for a little extra protection against corrosion, keep the engine and carb clean and your engines will last quite a long time.
The advice woody28 gave you, is for the most part correct, but it does not apply to your engine as it is an ABC engine and has no ring.
As far as your idle goes, its kinda hard to help you with that in this format. I can't hear or see the engine running.If it will hold a reliable idle and transition smoothly to wide open throttle , I think you are OK.
Consider the books I recommended, I think you would really like them. A lot of the questions you are asking are covered in specific detail along with photos and illustrations.

Thanks I will look into buying the books . I just hope they are not to expensive.