What's wrong with the OS LA series?

Almost everyone I speak to about getting my first plane qualifies the O.S.
engine choice with, "Just make sure it's not the LA series."
Whenever you see an RTF or ARF model that comes with the radio, etc, the
Engine is usually an LA.
What's wrong with the LA? Is whatever is bad about it so bad that you'd
spend another $100+ to get another engine for the RTF model?
One guy said it was "mushy" but I have no idea what that means. Is this
engine snobbery or a legitimate problem?
I can understand avoiding it (if there are problems with it) when buying
just an engine, but is the engine so horrible that I have to pass on buying
a model because it comes with one?
Reply to
Mike Szewczyk
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I have never had one so take this with a big lump of salt.
From what I have gleaned from pretty much lurking this group for a while is that the LA series are fine engines. It is a bushed engine ( instead of bearings ). It is not an engine that you think of when the word "power" pops into your head. It should have enough power to pull a trainer or other "low" performance planes around the sky, but, don't expect 45 degree climbouts. I suspect that since it is bushed it will wear out faster.
I think the prevailing thought is that if you get a "better" engine up front you will save money in the long run because you can put it in your next plane as you grow in the hobby. Engines typically outlast the airframes.
You can search the Google archives for it and get plenty of views one way or the other.
Douglas Kaip
"Mike Szewczyk hcgi.com>" Almost everyone I speak to about getting my first plane qualifies the O.S.
Reply to
Douglas Kaip
"Mike Szewczyk hcgi.com>" Almost everyone I speak to about getting my first plane qualifies the O.S.
The OS .15LA is a fine engine, actually one of the most powerful in it's size, great bang for the buck.
The rest of them, and ESPECIALLY the .40, are very weak, and they vibrate too much. That .40 has about the power that a .25 should have, it's actually quite sad. An O.S. .40LA on a 6 lb+. trainer is not much fun at all, and you have very little, or no, power reserve to get out of a jam, like driving a full size truck with a 4-banger under the hood. Do yourself a favor, if you HAVE to stick a .40, get the TT .42Gp or the Evolution .40NT or just about anyone else's .40, or better yet, skip the whole size and get a TT .46 Pro and never look back.
Reply to
Frank Costa
A correction. The O.S. .65LA is by some accounts a strong running engine, so I guess my comments apply basically to the .40. The .25 I haven't heard much about. A friend had one and wasn't very impressed.
Reply to
Frank Costa
Well, that's sort of my point. It comes on the model. It's my first model. Do I add $100 to the price of my first model to switch out the the LA motor that's on it? Is it THAT bad?
Reply to
Mike Szewczyk
Nothing that isn't wrong with any other engine. IOW, they're OK.
Reply to
Gregg Uhlendorf
There are RTF trainers that come with other motors. Horizon Hobby has a few trainers that come with the Evolution engine. The .40LA trainer WILL fly, though, don't get me wrong, so you can go ahead and get that one and hold off on any further engine purchases until you've made a decision on whether the engine has enough power for your own personnel taste.
"Mike Szewczyk hcgi.com>" > The rest of them, and ESPECIALLY the .40, are very weak, and they vibrate
Reply to
Frank Costa
Low power (bushed bearing instead of ball bearings).
Japanese-philips screw heads instead of hex heads holding the cylinder-head on.
Remote needle valve.
Plastic or nylon back plate? Don't overtighten if it is a non-metallic part.
If you're determined to buy an RTF, either look for one that doesn't have the LA--I'm pretty sure that there are TT RTF kits and ... the "Evolution" series. I'd bet that these don't cost $100 more than an LA-equipped RTF, but I don't know for sure.
It's a way of saying "low-power".
Nope. You can learn to fly with it. 95% of OS engines are easy to start, quiet, durable, and reliable. Try the engine yourself and see if you like it.
Marty
Reply to
Martin X. Moleski, SJ
"Mike Szewczyk hcgi.com>" > The rest of them, and ESPECIALLY the .40, are very weak, and they vibrate
For what's it's worth, I have had the .15la, .40la, .46la, and .65la, and they all have been great engines, and after only four years of flying, only the .15la is no longer used, because it got planted 6" in to the ground. not the engines fault. you have to understand that the "La" engines are O.S.'s low cost engines, to help get people into flying, they are a good decent engine for the money.
this is only my opinion, and there for no one is held responsible for my thoughts
thank you
Reply to
Skybomb
The LA is a low-power engine for the size. It is bushed instead of ball-bearing and has an air-bleed carburator. This carb may be difficult to adjust at idle. The air bleed hole often doesn't let in enough air to properly lean the mixture.
As someone else said, don't overtighten the screws in the plastic backplate.
It's a good .30-size engine in a .40-size package.
I have heard excellent reports about the Evolution engine and I know the TT Pro series are excellent as well.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
I own a very used 40-LA on my ol' beater, an Avistar trainer(~5.5 lb.) that has been used to fully train two pilots through plenty of 'jams', and flown a lot since. Swinging an APC 10x6 on 10% nitro, it still has plenty of power for the application. I even get several seconds of hang- time on the vertical. It doesn't vibrate more than any other 2-stroke I've owned. It starts and runs reliably. My only dislike is the well known "LA Rattle" sound at low throttle. Though that's just a benign annoyance for sure.
I recently flew it at a fun-fly where one task was a dead stick duration contest, a 25 sec. full power climb out from takeoff to shutdown. I estimate it climbed at a constant 35-40 deg., and after 25 sec. it was a speck.
IMO, of course it's not the best engine. It's a low budget engine. But, for the money, it certainly does the job.
Reply to
Gregg Uhlendorf
On 7/15/2004 12:20 PM Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:
20 years ago they were a decent engine. With the changing times and improvements in technology they are weak engines. They are a bushed bearing engine that uses 20 year old technology.
To get a better idea of what people mean when they say the engine is weak, go to the Tower site
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and compare the horse power ratings on the OS 40 LA and the OS 40FX/AX, also compare the horse power of the OS 46LA and the OS 46 FX/AX, Thunder Tiger Pro 46, GMS 46, etc.
The numbers will tell you. While you are at it compare the price of an OS 40LA to a Super Tiger 40 or an OS 46LA engine against the Thunder Tiger Pro 46, Tower 46 (made by GMS, but not as good) and the GMS 46.
You will find that for a little difference in cost, you get A LOT MORE POWER.
I ALWAYS tell people to buy everything separately. Yes, it costs a little more up front, but you have something decent to work with and you don't have to go out and buy another engine or different brand transmitter or a "Buddy Box" (since no one at your site can "buddy box" to your transmitter) or a computer radio 6 months down the road because the "BASE" level radio can not do anything except the bare basics.
Reply to
Ted Campanelli
I hit the wrong button....here's the rest of my reply.
You don't have to spend another $100. Tower Hobbies lists the OS .46 AX as $114.99 and the OS .40LA as $56.99. The AX series has more power and will last through several sport model planes.
As others have suggested, look for different trainer packages that do not include the LA. The LA will fly a 5-lb. trainer, but doesn't have much reserve power to get out of trouble.
Here's a good example: An OS .40 LA won't spin a 10x4 prop as fast as my OS .32 SX or my Webra Speed .32. Neither of these engines is a good choice for a .40 trainer, either.
As I and others have mentioned before, take a look at the Evolution, TT Pro, and the OS AX. I believe these engines will give you more flyability and satisfaction for the money.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Have you already purchased the LA-equipped trainer?
If so, go fly it, have fun, and let us know what you think afterward.
If not, you might shop for something with a slightly stouter powerplant.
In our club, we fly from grass and have lots of wind in the 8-15 mph range. Ball-bearing .40s have proven far superior to the plain-bearing engines for takeoff and training.
Marty
Reply to
Martin X. Moleski, SJ
I haven't gotten one yet. But there's one hanging in a local hobby shop that's a good deal (consignment) but it has the LA engine. If that one is gone when I actually have the money, I'll shop for one sans-LA.
Reply to
Mike Szewczyk
Previously known as the "FP Rattle." ;o)
It may be common to all bearing engines. I don't remember whether my TT .25 GP rattles.
That reminds me of a virtue of the plain-bearing engines: they weigh less than the ball-bearing engines by five or six ounces and can take a lot of abuse.
Marty
Reply to
Martin X. Moleski, SJ
Ever watched the behaviour of sheep? There's your answer.
That's primarily because of three influential factors. (a) it's inexpensive (relative to other, particularly other OS, engines); (b) it's perfectly suited powerwise to it's intended introductory and training role, and; (c) it is reliable, robust internally, simple, easy to tune (conservative intake diameter oriface with air bleed carb) with a stable idle.
The LA is only power the models. To empower the insecure ego you need to spend more. ;P
Rationalising snobbery, elitism driven ignorance - call it what you will. Experienced flyers might desire more power for certain tasks, but for the training role, the power delivery & throttle response of the LA is as good as any similar plain bearing engine in its class with the restrictions imposed by (a) a conservative venturi diameter but more importantly (b) the delayed tuning response from a remote needle off a low (muffler) pressure fuel feed.
Although I prefer O.S's predecessor the FP, for the training role or one where its performance class is not restrictive the LA appears quite OK. The ones that I've seen in operation seem to respond the same as any other engine to dickheads. If it's a dickhead using it, they'll have the usual dickhead incurred problems no matter which brand or design they choose. The LA just becames the new and an easy whipping boy because it's blue & prominent, it's ugly and it's different (new). You used to hear the same shit about the FP, though not to the same extent when it was the intro engine.
Reply to
K
The answer to your question is do you need a shotgun to kill a mouse? Will a sledgehammer serve you better than a cabinetmaker's tack hammer in building a fine piece of furniture. The moral here is use the right tool for the best result. Same applies to learning to fly.
Save the $100- and spend it one an another engine when you actually know what you want. In the meantime, you'll have a great time learning with the LA and can onsell it when you're finished to many an eager beaver if you no longer require it. The buying for later (your next plane) argument is not only a false economy, it is actually a false premise when examined logically and intelligently.
Reply to
K
My first purchase was a LA40, I put it on a LT-40 Sig. It was marginal in power but taught me to fly. It's on a LT-25 now and makes a great combination on the lighter airframe.
It's always been a sweetheart to run, with a good idle and one-flip starts.
For a low-cost kit trainer, a LT-25 with the LA40 is hard to beat! I wouldn't buy another one, but I've had great service from the one I have.
Reply to
Dan
K posted message IDon Fri, 16 Jul 2004 08:47:35 +1000
You should be more careful with your name-calling. Paul McIntosh is very sensitive and easily bruised.
Reply to
Todd Klondike

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