I just bought a Mecoa .46 from my local hobby shop. The store owner didn't know much about the engine, as he was selling it for someone else. He had "Like New" marked on the tag and had it marked for $60.00 (it didn't come with a box or manual). The engine did appear to be used, but very little. I took the muffler off of it to inspect the piston, and to my suprise the piston appeared to be "new". It looked as if the engine had never even been cranked/started/ran. It had no scratches or discoloration at all. The compression was super strong. It didn't have a prop on it, and I couldn't turn over the crank by hand. The engine seemed to be brand spanking new, other than a tiny bit of crud on the outer part of the case, so I decided to buy it.

Since it didn't come with a box or manual, I went to the Mecoa website to find out as much as I could about the engine, since I knew/know nothing about Mecoa's. It gave the break-in procedure, and I noticed that it gave instructions to break it in by the fourstroke method. It never mentioned leaning the needle sparingly, like I have always done with my FX's and other ABC engines in the past. Should I break in the engine by the instructions or should I use the "run it near lean and then fourstroke it for a bit" method?

Also, did I get a good deal on this engine, and what can expect from it performance wise? I'm going to be using it on a Spa3d turning a 11X4 APC prop.

Thanks in advance,
John

John...

Put yourself in the warranty department at MECOA.

"The guy followed our instructions"

"The guy didn't follow our instructions"

Which is more likely to get a warranty repair if needed?

We can think what we like, but the mfr of the motor has the final say.

'Race

Race,

It's a second-hand, used engine. The warranty is void now anyway. So, what difference does it matter about the warranty? I'm simply wanting to know if the Mecoa break-in procedure is correct for its ABC engine. O.S. published an incorrect break-in procedure for the .46 FX, a procedure that sounds a lot like that of the Mecoa. Since I don't have a warranty, I want to break in the engine in a way that will be correct for an ABC engine. Just because an engine manufacturer states how to break in their engines, it doesn't always mean that it's the correct way (O.S. is an example of that). For now, I need replies from people who "know" what needs to be done, maybe from people who have broken in this engine.

'Dart...

I know what your saying, and I don't disagree entirely with your thought processes
regarding the matter.

HOWEVER...why (oh WHY!) would MECOA (the mfr) suggest that the motor be run-in
in a manner that would damage it?

Trust me...there is NO money in customer returns.

I don't want to hear the OS story on the .46FX. That's not the point.

Truth is, too many people without the experience to back them up believe that they are
smarter than the people who designed the product.

On that...I respectfully disagree. From experience.

Bottom line: It's your cash. Do it your way. If it works out great that's wonderful.

If not...you know who to blame.....right?

'Race

John, Curt,

The manufacturer's warranty department has neither the time, nor a great method, to ascertain the break-in method that you used. So your warranty would not have suffered anyway; even if it had been in effect.

So, if I get an engine to break-in, I don't even read the instructions, but do the break-in using the method, which is the most appropriate for that type of engine.

In this case, I don't mind what Randy (Mecoa) says and I am sure he will not go against me.
This because the break-in instructions in the Mecoa web site, for the K&B 4800, specifically say that ALL tapered bore engines must be broken-in, at a rich two-cycle setting.

So this rich two-cycle is the method I would use.

regardless of what the instructions say, the proper way for an ABC/ABN 2 cycle breakin does not change. so even what they suggest may not be ideal. give it the correct non-4 cycling 2 min run heat cycle cool down runs. even if the directions say to 4 cycle it, savvy engine folks know thats wrong. even most of us know OS 4 cycling breakin method is totally incorrect for abc/abn 2 stroke engines. go with the 2 min runs at a semi rich non 4 cycling and let cool down fully between runs.

John,

The MECOA .46 R/C is a great engine for LOW $$$. I broke mine in as Dar recomends.
Put a Tower muffler on it and gained aprox 400 RPM. I have since converted it to Diesel and get
13,000RPM on a 11x6 black master airscrew prop. A number of my friends have 2 or 3 of them.
I do not know why anyone would pay double for an OS .46 FX?


Francis

I don't disagree one iota with the hotter/faster break in for an ABC/ABN type engine.

Still...the message sent to a newcomers is the same. "Disregard the instructions"

Let the destruction begin and the subsequent 500 posts on "what is wrong with my
brand X motor...."

????

What are you gonna do?

<GGGG>

'Race

To all who have given a response,

This is what I'm going to do:

1. Start the engine and allow it to idle for approximately 20 seconds to let it warm.

2. Run up the engine and adjust the needle to a "slightly rich" setting (not four stroke rich). Run the engine at WOT for two minutes. When the two minutes is up, kill the engine and allow it to completely cool.

3. Repeat step No. 2 about 10 times.

4. Lean the needle to normal flying setting and go fly.

Is this correct, yes or no, and if not, what do I need to do differently?

Thanks,
John

Curt,

By all probability, you are more likely to get exactly this result, if they all follow the manufacturer's break-in instructions...

There is another thread, started by someone with an OS.46LA, that probably did follow the instructions.
He has a gallon of fuel through the engine and still cannot get it to run right.

John,

That's exactly the right way to do it!

Alrighty then! Now we're getting somewhere!

Another question. About killing the engine to let it completely cool down, would it be OK to four stroke the engine to cool it off, and then after it is cool enough to be able to be held by the hand, run it WOT for another two minutes at the previous needle setting? Or, does it need to "completely" cool, by shutting off the engine? Seems that by four stroking it, I would still be letting it cool, but saving time instead of just sitting there dead, while cooling.

dar...

Chalk it up to inexperience perhaps, but in the scant days since I started in 1977, I have seen
more than just one motor bunged up by the user... (re: OS46LA)

I agree on the hotter break in for any ABC/ABN engine period.

My beef is with the perception that a newsgroup can provide "better"
information than the people who made the d_mned product in question.


?????


If I tell you to run your car without oil "for better acceleration"....are ya gonna do it?

'Race

heh heh...

Do you see my frustration here?

That users (new and old) are told almost without fail that the mfr does NOT
know what they're saying?

THAT is my gripe.

Hey...it's a cheap, knock off engine, and if it lasts it's first three outings before taking a
dirt nap...it's a bargain by the standards applied by most.

So there you go kids. Buy stuff with no warranty...and hope for the best.

'Race

Race,

It's not like I make it a habit of buying used engines, but if I do, I try to do my homework before I buy. Like I said in my initial post, the engine appears to have never been run. I'm just trying to make sure I break in the engine the way it's supposed to be. I've never had any experience with Mecoa. I have bought several used engines in the past, and all have ran perfectly, but it's like I said before, I try to do my homework before buying. In fact, out of all of the numerous new engines I've bought in the past, I've never had to warranty one. Evidently I'm doing something right. Anyway, to go against what you stated, there is nothing wrong with buying a used engine without a warranty as long as you check it out thouroughly before buying it, even if it means running it before buying. And sometimes, you may get a heap of crap you can do nothing with. It's not a complete gamble though.

Dart..

I'm with you 100%.!!!!!!!!!

Trust me.

Sounds like you probably did fine in your dealings.

I just CANNOT in good faith, instruct a fellow modeler to do something inconsistent with
the guidelines provided by the mfr of the product in question....My "opinion" does not count
for a whole lot when someone else's money is on the line.

See what I'm getting at?

I hope that puppy screams for ya....

Best regards,

Race

NO[:@]NO[:@]NO[:@]NO
Yard dart if what you mean by that is that to cool off the engine you're not going to stop it and let it cool but rather reduce throttle and let it cool until you can touch it and ther up the revs and lean it again... you are killing the poor engine!!!!
the only way to cool it off is to stop the engine and cool it off!! the whole point of the experience is to run the engine as hot as possible to properly seat the piston/liner combo....

Swamp,

I understand! The engine will be stopped to cool it off.

Thanks,

John

I have another question, but first, let me stress again that I really don't "exactly" how much this engine has been ran. I know it's been cranked, but that's about all I can tell. Someone asked me if the piston/cylinder had a "pinch" at TDC. I understand exactly what they were asking, but I have actualy experienced very few engines that had a noticable amount of pinch straight out of the box. This engine, from what I can tell, really doesn't have any. I do know that the Tower brand engines have an enormous amount of pinch right out of the box, so much they sqeak at TDC. Since my engine really doesn't have any, is this a way to tell if the engine has had any significant run-in time on it? It does have a ton of compression. Does this tell me anything? I have noticed on several .46 FX engines that there's really no pinch, just a lot of compression.

The whole point of me starting this post is to find out of anyone can give me any hints as to what to look for to tell if the engine has has any run/break-in time on it.

Thanks,
John

John,

You stated in your first post that the engine didn't seem to have been run.
Tapered bore engines, of all types, if properly manufactured, must have an interference fit of the piston at TDC.

This interference fit must not be totally worn away, even after break-in and many running hours.
In the [link=http://www.jettengineering.com/]Jett Engineering web site[/link] technical section, Dub Jett says this:

Jetts are tight coming from the factory. It has always been a source of annoyance for me to buy a new engine and find that it is already too loose, even before it has been cranked up! ABC and AAC engines run better and produce more power when they are tight, and by the time there is no "pinch" left (bump at top dead center) the engine is starting to lose some of its power. So if your engine is "too tight" coming from the factory, be happy that you are getting your money’s worth in life and power.

To check if your engine still has a pinch, remove the plug and the back-plate and turn the engine over TDC.
With no upper, or lower compression, this pinch will be felt; unless it doesn't exist.

Seen her run today yard-dart and looked like she did pretty good. It yanked that plane OUT of a hover like nobody's business.....
See you later dude


Shane

Shane's right, the engine ran perfectly. Turning an APC 11x4 prop, it would pull my 4.5 .lb Spa3d out of hover like a rocket. Someone here on RCU compared the Mecoa .46 to a .46FX, saying that the two were a lot a like in performance. I have to agree, they are very close in performance. I haven't yet tried a 12X4 prop on it yet, like everyone is running on the FX. I'm sure there will be some difference in performance but not much. I believe that the Mecoa is a great engine for the listed $69.

John