bman1128

Easy Guys....

I have read many heated threads on engine breakin... and only care to hear from people who have done it with OS 40 LA...I bought new one off eBay....no box, but do have manual and i will read it to see what instructions say to do...

Experience is a good teacher as well ....so if you have a good running OS 40 LA that YOU broke in.... please let me know how you did it.

thanks,

RC_Junky

My Feedback: (1)

I have broken in several LA .40's, on new guys trainers and one for myself that I put of a Pizza Box. I did exactly as the manual says, they all ran fine and was ready to fly after about 3 tanks. Good luck.

TTARK

First off ignore the book, it is a misprint. Doing it by the book will only ruin your engine. I have broken in several of these engines and never had a problem with them. First start the engine and get it almost peaked, as SOON as it peaks, richen it about 1/2 turn on the needle valve. Run at 3/4 to full throttle for a tank of fuel. Let the engine cool and then restart the engine, and go fly the plane at about 1/4 turn rich. then over the next few tanks of fuel gradually lean the engine out on sucessive flights until peaked ( about 4 or five tanks)

Terry

smokingcrater

broke in exactly as the manual states, still is probably my easiest starting engine that I own... decent power for a little .40, and never a problem...

BotleRocketWar

I pretty much do it just like Terry...I've broken-in about 5 of them.

It's going to be a weak engine regardless of the break-in!

Casey Frost

My Feedback: (1)

I broke in my OS .40 LA just as the manual said to and it runs perfectly. It was more difficult to start while it was new, but once it was run it, just prime it, flick it and your off. No adjustments needed, just fly. I have it on my PT-40 and must have put a hundred flights on it by now(thats a conservative estimate) and there's no fuel leaking from the front bushing or anywhere else. Also, once broken in, I switched from 5% nitro to 15% and removed the Master Airscrew and installed and APC and it made a very noticable difference...about 1500 RPM. It turns in the low to mid 11's right now and I run it in the low 11's.

I broke it in with the 12x6 Master Airscrew and 5% to keep the RPM's in check and the heat down and it seems to have worked. This thing turned out to be a great little motor.

bman1128

Any others agree with this? Why would they send out a book with mistakes in it? Find that hard to believe, especially if their directions caused people to lose their engines... ???... You cant stay in business like that!

thanks

BotleRocketWar

Yeah, I agree!!

Good question...

TTARK

But it is true, there are several threads on here referring to the mistake in the book, including some by Ann Marie Cross. There is a definate mistake in the book and a two stoke engine needs to heat up to get it broken in right. Four stroking the engine as recommended in the book does not allow the engine to heat up enough. Bring the engine to a rich two stoke rpm and let it run for a tank of fuel. the gradually lean it with sucessive runs letting it cool between tanks. You can fly it rich on the second flight

Terry

bman1128

You may be right....some guys at the field agreed that the book is not right... I will continue to look into this further...

So what is SO wrong with OS that they continue to let a mistake be printed in their book... you'd think they would correct it...

or do they think it is right?

Maybe they printed 10 billion copies and cant afford to reprint...
i just dont get that!

frustrating...

Another FRUSTRATING thing is why there is so much disagreement over this topic...kind of makes me think that maybe an engine would work right regardless of the approach... otherwise it would seem more people would be in agreement....

Anyway... some people argue that these engines are so well made that you can almost just slap 'em in a plane and run em and you'd be alright...

However, I do plan on doing a breakin tank or two....depending on when i decide how to break them in...

I do thank you for your input!!!

BotleRocketWar

Didn't know there was a lot of disagreement on this topic...

Anybody who knows a fair amount about this type of engine can tell you 4 cycling it or running it slobbering rich is bad for it. Then they can tell you that the isntructions ARE wrong. There is no disagreement... There is no disagreement that you have to do the opposite for a ringed engine.

I think the reason there aern't more complaints about these engines after break-in is bceause most people don't follow the isntructions ANYWAY. Most will see that the engine runs fine on the first tank and will decide it doesn't need break-in and they will just go fly it. The truth is, that's almost as good as the proper break-in on the ground...