RE: How important is the break in procedure?
 

G'day

I think everyone has now covered all the basics.

1. Get the tank in the right position if you can. Centre line of the tank in line with the carby.
2. Make sure there are no splits or holes in tubing and that the clunk is at the back of the tank. It is best to cut tube with a sharp knife and not side cutters which tend to crush and split the tube. Check for bubbles in the fuel line. They can be because of holes but they can also be because the fuel is foaming. Packing the fuel tank in foam reduces this and there are also special anti foaming clunks and tanks.
3. Use fresh fuel. Nothing spoils an idle like water in the fuel and methanol just loves to absorb water.
4. Good plug. OS 8, Enya 3 etc.
5. Start with the air bleed about half open (it is not critical initially) and tune the top end to be a little rich. As you said, doing this on a near empty tank will solve the leaning problem but you may then find that on a full tank is it just too rich to fly. This is where the uniflow double clunk tank approach comes in. Saito also say to tune their engines this way.

Finally. Your LA is a high quality Japanese engine but it is also a basic two stroke engine. Don't expect miracles from it. It has been built to be simple and easy to start and economical to run as well as tough. It is not a high performance engine by any means but a light reliable slugger. They don't run all that smoothly at idle but this is not really a problem. The occasional blip on the throttle will clear them out enough to get some flying done. They do tend to improve as they get more running and as you get better at knowing what they need. I had one in a simple trainer at one stage. The combination was so good that I rarely got to fly it because everyone else used to borrow it to teach newcomers.

All the best and keep asking questions and making mistakes. That is how we all learn.

RE: How important is the break in procedure?
 

Ok guys and girls. It was not a good day at the flying field although it could have been. Beautiful weather here today and the club had its meeting at the field with lost of folks flying. My flight was really short however because as soon as I took off and made one pass, the engine lost power and got really loud. I had trouble bringing her in for a hard landing to discover I had lost the tail end of the muffler. That single long bolt that holds the end of the muffler on is gone along with the baffle and the end of the muffler. Looked everywhere but of course it's lost.

This OS46 LA is giving me the fits! I spent some time yesterday removing the engine, fuel tank and fuel lines. Checked the fuel lines and tank over carefully. No leaks so I'm at a loss as to why I can still see air bubbles in the fuel line, sometimes causing the engine to stumble. As for tuning - she was running really rich but would transition well and reach full power when asked. I did convert the fuel line to the uni-flow by adding another line and clunk and except for being a little trouble to fill up I figured this would aid in preventing the leaning out problem. Never really got to find out however and until I get a new muffler the 46LA is grounded. The only thing I can guess is while I was tinkering, the excessive vibration must have loosed the nut holding on the muffler and I just didn't notice so...

I may just remove the engine and tank again and run this engine on the bench. It looks like a new muffler is about $25 - $30 plus shipping. I may just be better off just getting a better engine. Gotta think about it.

Thanks for all the input guys. I wont give up on this engine just yet as I still think its just not tuned right. But right now it's cutting into my flying time too much. And it's difficult not to think that its just a poor running engine. Still, I'll probably call tower on Monday and order the muffler. But maybe I should be ordering a better engine too and shelve the LA.

Shaggy

RE: How important is the break in procedure?
 

Hey Shaggy did you run over a black cat ? Is your tank wraped in foam and not touching any of the fuz? Not sure if any one has mentioned this. Cheers the pope

RE: How important is the break in procedure?
 

Shaggy,

I had another engine that ran awful. It is supposed to be a great engine but would not idle. When I flew I ran it WOT until I wanted to land then did a dead stick landing. One day I took the 'O' ring off the carb and turned it over (it was an old engine and the ring had formed to the two surfaces) the engine ran fine after that! I did not turn the ring over until after I had bought another engine so I could fly the plane.

I would buy a new engine so you can fly, fiddle with the other one on rainy days til you got it running good then buy a plane to go with the engine after you fix it. That is what I did. Hate to have a perfectly good engine just sitting there.

Good luck!

RE: How important is the break in procedure?
 

Hi!
Those split silencers can be a nuisance.
I bolt the parts together and at the same time use silicon for keeping it tight!
If you have air coming in the lines ...you have got a leak somewhere...simple as that!

Best way of getting rid of air leaks and having the best tank available is getting a Tettra "Bubbleless tank! It's used in pylon racing world wide.

RE: How important is the break in procedure?
 

G'day

Bummer. But then again, lots of two stroke mufflers fall apart. The pylon boys here use Thunder Tiger 46 pro engines and they all wire their mufflers as they are fed up with buying new ones because they have lost the back half.

But frankly, if you cannot get an LA to run, you need to be a bit careful about other engine purchases. I am trying to get a Super Tigre 51 to run well at the moment and so far all I am getting is dead sticks when I touch the throttle. It just needs more running and tuning and will be Ok eventually but for the moment I have replaced it with a four stroke. I have found four strokes much easier to live with for general flying. They are dearer, more complex and do need some maintenance from time to time but they do sound nice, they use less fuel and they are easier to make reliable. I have just been doing a bit of a marathon flying exercise. I flew every day last week. I flew 10 different planes using 12 different engines and the only one that gave any problems was a two stroke glow. (The two stroke diesel was fine). One was electric but all the rest were four strokes. All started easily, and all ran perfectly.

I particularly like Saitos and Lasers but my OS and ASP engines also ran fine. I did have some minor problems with two Thunder Tigers I got cheaply (stripped prop nuts which I will replace with OS ones) but they did run perfectly.

So. How about a nice four stroke? ASP and Magnum are essentially the same and are quite cheap at the moment especially from Hong Kong. I have had good results with both. Saito and OS are dearer (especially the new Alpha series OS) but they are quality Japanese engines. I fired up an OS 81 Alpha for the first time yesterday. I think it is going to be an excellent engine.

I like Saitos as they are reasonably priced and look like real old style aero engines. They also are light and powerful for their weight. A FA-56 is a good starting point for a 40 size model but you can put the 62 and the 72 and even the 82 into the same mount.

I also love my Lasers from England. A bit on the pricey side but built like a tank and extremely easy to get to run well. And they sound brilliant.

Finally, if you want another two stroke 46, the OS 46 AX is my choice for an all round engine. There are cheaper engines and there are faster engines but the AX is the best all rounder in my opinion. We have some really tough engine users at my club and the engine they don't seem to have problems with is the 46 AX. I have one and it is a very nice easy to use engine. My mates are rather brutal on their engines but the AX 46 keeps on working well though I suspect that the way they use them, they are not going to last as long as they should.

Anyway, don't give up. Hang in there and have fun.

RE: How important is the break in procedure?
 

If I ran over a black cat I didn't see it...

But I'm learning a lot with this tower trainer and 46 LA. I've decided not to get another engine for this particular airplane for several reasons. First I have the problem with the engine, and second the problem of air getting into the fuel line. Third, I think the top of the fuel when the tank is full is just at about even with the carb. But this is how this model was designed. Maybe I'll get a smaller tank and then I'll have some room to wrap it in foam and wedge it higher in the fuse. So I've ordered a new muffler and will take some measures to try not to have the back half fall off again. Maybe a lock nut and some RTV.

If I still don't get this engine running right after all that I'll consider a different engine then, assuming I still dont have trouble with air in the lines. But there's another thing yet. This engine is not really bolted to the motor mount, it is bracketed to the mount with two plates. Every time I take the engine off I have to fiddle with those silly metal plates. This is the last time I buy a model that uses this method of mounting the engine. Anyone familiar with this? I called tower and asked them about this and they really didn't have a good answer. The problem with this method and this engine is one of the bolts holding the bracketing plates, sits right under the remote needle valve. so it's a bugger to tighten that bolt. So no matter what you do, you get to fly with 3 tight mounting bolt and 1 you're sure isn't tight enough. They suggested I remove the remote needle valve to mount and remove the engine.
I asked em how about a motor mount that fits the dang engine?

Shaggy

RE: How important is the break in procedure?
 

I hate those mounts and won't use them. Good point.

RE: How important is the break in procedure?
 

Hi!
If you have the top of the fuel level at the same level as the carb then you have the engine mounted to high(or tank to low) ! I know that this is a manufacturer error on most trainers , but you as a modeler have to fix it if you want your engine to perform as it should!
....That's why I always mount my engines on their sides.

RE: How important is the break in procedure?
 

Hey jaka- how do those Tetra tanks hold up to a pumped engine like those offered by OS and YS? Do you know if they last without leaking over time?

RE: How important is the break in procedure?
 

Hi!
No problems!

RE: How important is the break in procedure?
 

Jaka,
You're right. I might just do that!

Thanks
Shaggy

RE: How important is the break in procedure?
 

I just picked up a new LA .46/S. It still has a very stout pinch near TDC even after about 45 minutes of running...so stout, its one of a very few engines I bother to put a leather glove on to flip even though it seems to have found its "happy place" and is starting with one flick now.

RE: How important is the break in procedure?
 

Shaggy,

When you changed all the fuel lines, did that include the internal tank line between the clunk and the bung? If that line has a split about the half tank level it would explain why the engine runs fine until about half a tank.

Apologies if you have already tried that.

Dave H

RE: How important is the break in procedure?
 

http://www.rcuniverse.com/forum/m_1890371/tm.htm [sm=thumbup.gif]

RE: How important is the break in procedure?
 

Quote:

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ORIGINAL: Broken Wings

http://www.rcuniverse.com/forum/m_1890371/tm.htm [sm=thumbup.gif]

---

BW,


Do read and fully comprehend the context of that thread.

Make sure you understand why my qustion was asked in the first place; and why Bob's replies were exactly what I wanted to hear.


It also hints why the manufacturer's instructions are often not the best advice.
And also also why some engine designed to be easy to begin with; i.e. that hardly need any *real* break-in procedure, will eventually not last for very long in normal use.

It explains why is among the more popular in this forum, among 'normal' threads; with over 29,000 hits.

RE: How important is the break in procedure?
 

Quote:

---

ORIGINAL: Broken Wings

http://www.rcuniverse.com/forum/m_1890371/tm.htm [sm=thumbup.gif]

---

BW,


Do read and fully comprehend the context of that thread.

Make sure you understand why my qustion was asked in the first place; and why Bob's replies were exactly what I wanted to hear.


It also hints why the manufacturer's instructions are often not the best advice.
And also why some engine designed to be easy to begin with; i.e. that hardly need any *real* break-in procedure, will eventually not last for very long in normal use.

It explains why [link=http://www.rcuniverse.com/forum/m_1850473/tm.htm]this thread[/link] is among the more popular in this forum, among the 'normal' threads; with over 29,000 hits.

RE: How important is the break in procedure?
 

Good day, Dar!

Thank for posting the link to that other thread. I bookmarked it for future reference.

RE: How important is the break in procedure?
 

http://www.rcuniverse.com/forum/fb.asp?m=9798458

I'll go with Bob's reply to your question. (If you already knew, why did you ask?)...

Until you understand that different manufacturers use different materials to manufacture engines, your "one size fits all" procedure is irresponsible at best. (In my opinion.)


http://www.rcuniverse.com/forum/fb.asp?m=9803650
Sorry Dar, All "Brass is not Brass". Some manufactures liners are made up of much harder material (less expensive) than others and will need a different break-in procedure.

"whatever alloy is used".....??? Really?


That's what Bob was trying to explain to you when he said "There is some good and bad information out there about break in proceedures for ABC type engines...... some info is a mixture of both. In general, a proceedure outline by an engine manufacturer should be followed as written. "

RE: How important is the break in procedure?
 

Glad you posted this, I was wondering if he had checked the internal lines too. While there could be other reasons, his description of the symptoms is consistent with a split in the internal fuel line. This is common enough it ought to be checked.

Mind you the thread is two months old, I wonder if he got it figured out.

RE: How important is the break in procedure?
 

BW,


As I wrote, break-in is type-specific.

All ABC/ABN/AAC/ABL engines require the same technique. Whether they are made by OS, Super Tigre, Rossi, Jett, or any other manufacturer; the materials are close enough for the proper break-in procedure not to change.
Jett engineering, for example, do not bother to differentiate between their ABC and AAC engines in [link=http://jettengineering.com/tech/breakin.html]their break-in instructions[/link], because the materials and machining are similar enough.
This, even though one type uses aluminium for the sleeve's base metal; and the other brass. Different metals - same technique, because the design is virtually the same tapered-bore arrangement!

And in regards to OS; if you owned a .46FX, would you follow the technique outlined in [link=http://manuals.hobbico.com/osm/50sx-40-46-61-91fx-manual.pdf]this manual[/link], which was written for both ringed (.50SX and .91FX) and ABN (.40FX, .46FX and .61FX) engines; and does not bother to differentiate between the two types; or would you follow [link=http://osengines.com/faq/product-faq.html#q2]this passage[/link]?

Both were written by OS for the .46FX, so which one is right?

Manuals are usually written; at least the inaccurate ones, by the manufacturers' PR departments, so they would be 'easier' to follow... Not by the technical people who should be doing it.


I think it is about time somone breaks your wings!... Oh, they're already broken...[&o]

RE: How important is the break in procedure?
 

John just think about this, 29,000 hits on a 10 minute, no brainer procedure has had me wondering for quite a while.

RE: How important is the break in procedure?
 

Quote:

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ORIGINAL: Hobbsy

John just think about this, 29,000 hits on a 10 minute, no brainer procedure has had me wondering for quite a while.

---

Dave,


The break-in thread had this number of views over its life, i.e. since 2004.

Compared to most other threads in this sub-forum (not including club threads, like the one of Saito owners), this is a significantly large number.

RE: How important is the break in procedure?
 

Dar, I know that this is a very important issue for you. (Perhaps to the point where you would like Somone to break my wings):D

Jett knows that the material used to manufacture their AAC and ABC cylinder liners have very similar material characteristics, they should as they specified the materials and manufactured the engines.

Just post a list of the material used to manufacture OS, Super Tigre, Rossi, Jett, or any other manufacturer.

We can them look up the various material specifications and compare them. (You can't because you don't know...that's what I'm trying to convey here.)

Your theory is nothing more than conjecture.

That is why Bob wrote "In general, a procedure outline by an engine manufacturer should be followed as written. " BECAUSE THEY KNOW WHAT THEY MADE THE PARTS OUT OF AND HOW THE ENGINE WAS DESIGNED!!!

I find it difficult to believe that you think that a Chinese engine manufacturer would use the same material as Jett or NovaRossi....

Le Fou gets it...[&o]

RE: How important is the break in procedure?
 

I like the monkey pictures in the thread...:D