Keep in mind, this is for a trainer, It will not do any acrobatics/3dflying. It will only be used to learn the basics, take off, and landings with a 48" high wing SPAD.

I spotted a MDS .48 engine at my local hobby shop for 109.00$ Canadian. I like the price (Compared to OS) and would like to purchase it. I've read several threads on this engine. some positive and some negative. I don't really mind playing around and tuning the engine, what better way to learn about glow engines...

It's my understanding that I should break the engine with 1 gallon of fuel and run this engine with 5% Nitro and a idle bar glow plug(Or in some post, number 8 OS Glow plug).

Am I correct in the statment above?

How many HP does this engine have? I heard 1.51 hp!

Any more tips on how to tune this engine? how to break it?


Regards,

Don't walk run from that engine. There no longer sold in the US. Most if not all gave people fitts. No mid range. Great power at full throttle. Needles would never stay set. Thats why the MDS is so cheap. Dennis

Thunder Tiger, OS LA (in spite of what some say), Super Tigre, and Magnum all have generally good reputations and have good prices. I have not seen many good comments about MDS. For a beginner plane you want reliability. Don't buy based on price alone.

MDS actually means -- mucking door stop. I nearly bought one on pure speculation, but a close friend did, so I just watched -- him scream & curse etc. It eventually broke its connecting rod. That was enough for me -- my curiosity was satisfied.

I still think for a trainer the best engine for overall reliablity\power\price\ease of use ratio you can't beat the Thunder Tiger engines.

The early MDS engines in the US had a carb that was junk. If you replaced the carb, you got a good engine out of the deal. MDS eventually replaced the carb with a slightly better design that some folks get working just fine. But for something that might have been gathering dust at the LHS, I'd probibly avoid the engine.

HP numbers for model engines are garbage. Just ignore anything said by any engine company about HP produced by their engine. They get those numbers by using an overly small prop and winding the engine way up to some seriously high RPM. It doesn't reflect the engine's torque curve, which is a more useful thing when it comes to actually moving airplanes around.

Ive got a few mds's, 12 i think. everyone runs great, one dead stick run it lean and it over heated. if i can find a new mds for a plane, i run them. make more power than the other engine in there size .

I have this engine on a Twist 40. It is a powerful, easy starting, reliable, sweet running engine. I bought it used on RCU for a very good (cheap) price because everyone knows this engine is no good and drives everyone crazy and has been found by the State of California to cause cancer and birth defects. Having said that, I don't think this is a best choice for a basic training engine. It makes a lot of power, certainly more than would be useful for a trainer. If you want to buy this engine for some future project down the road, go for it, but for a basic trainer, I recommend a Super Tigre 40 or OS 40/46 LA. These are economically priced engines that will give many years of service and would be excellent choices for your trainer. Good luck to you, whatever you choose.

DOn't but an LA series! They run fine but are seriously weak in power. They can barely get a trainer off the ground and forget moving them on to a sport plane later! [&o]

That's silly. The LA's have more power by far than implied by Fastsky.

If you only know how to take off by hauling hard back on the elevator and climbing nearly straight up, then yeah. But if you know how to fly, using the wing for lift, the .40 LA has plenty of power for a trainer. I've flown everything from an LT-40 to a superstar and my airvista on that engine, and it's fine. And I fly from a grass field that is sometimes not mowed very well. But I still have no problems. Now, you want to use an approprate prop of course. I like the APC 10x5 on the OS .40 LA. An 11x4 isn't bad either, though I mow too much grass with the 11" prop.

It's true that the LA's aren't very powerful for their displacement. But they have enough power to learn to fly, enough power to loop a trainer from level flight and do other basic aerobatics. You won't be able to climb vertically out of sight, but that's not a bad thing when learning to fly.

If you plan on taking the engine out and using it in a second plane, then it's probibly not the best choice. But a little secret, most guys actually don't do this. They keep the trainer flying while building the second plane, and end up buying a new engine anyway.

In the end, it's really not a big deal though.

Well, I put a lot of thought into this, and I rather spend the extra 50$ for a good engine! I'm thinking a OS .40FX or maybe, if my budget permits it, a OS .46AX. I already own a .25FX os engine and I never had a problem starting it or what not.

Thanks guys!

Good choice either one. I have both a 40FX and a 46FX engine and both have outlasted and out survived several planes. I bought the 40FX for my LT40 trainer and after I learned what I was doing I could hang on the prop at just over 1/2 throttle! [8D]

the la 46 is a verry good reliable engine with plenty of power ignore anyone who says otherwise!!its a verry good reliable engine for a trainer plane and will power any sports plane thats a 40 size!!!.sure theres more powerfull engines but if your new you shouldnt go near them yet!!!.stick with the os 46 la and you wont go far wrong.you seem to be posting this question quite a bit and this is the second time ive posted this answer .i hope this helps dont forget reliability is the most important thing!!.just read my other post on this engine and if you do buy one you wont regret it lol!!!.

Buy what you can afford and like knowing that regardless of brand it is possible to get a "bad" engine. With that said I like OS Thunder Tiger and Super Tiger. and I agree 10000% with Montague the LA engines a fine for a trainer if you DON'T try to take off like a rocket (i.e. straight up)

MDS= junk. I have a .46 la and I have it on a trainer. I pulls it allong just fine and it has about 4 gallons through it too, and has been run into pavmet HARD. and still runs like a champ.

Well it's was settle, I purchases a .46 LA yesterday for 93$ Canadian.

Thanks for all the comments!

Yep I got a .48 too and cant get it set right
Good low idle then WOT doesnt work
Then WOT works and then low idle doesnt
I heard the MDS stands for "Mostly Dead Stick"
LOL

i have an mds 78 on a super stick,i havent had any dead sticks with it,i have had problems with the carburetor loading up when i am coming in for touch and goes no mater how good the carburetor is adjusted it seems to change slightly when in the air,it takes a few seconds before it clears and then gets right back up to rpm.this engine to me isn't the best choice.i finally put an OS 60fx on it that engine seems to have much more power than the mds78 and no problems.i think the best choice engines to put on a trainer would be a thunder tiger 46pro,or like was said here one of the OS la series engines.

You mentioned this was for a SPAD. They don't build light weight SPADS so good choice picking the .46LA that is good for learning. You wil find when you want to move to a sport flyer that .46 will work but be a little less than what you want... I would have recomended the OS .46 FX or AX for future use. Good luck, have fun, DON"T GIVE UP!

This is coming from somebody who probably hasn't even tried this set up.

When I first got into glow planes, I bought a used .40 la along with the Hobbico Superstar and I ran the engine very rich not knowing and the the engine was powerful enough to fly my trainer inverted without a problem. Not only from opening the engine and seeing the black burnt oil inside I knew it was too rich, but while flying one day a guy just from hearing it said it didn't sound like it was getting as much power as it could.

I junked that one and bought a new one almost a year ago and put it on a P51 low wing trainer and it pulls it almost vertical .

I see you bought the .46 , although .40 doesn't seem much different from a .46 IT IS .... When I bought my OS .46fx and put it on my trainer I was shocked at the difference in flight characteristics.

Well found out I had a carb problem along with a air leak in the fuel line. Got a new carb and fixed the air leak and now it runs very strong. Only about 3 flights before Winter kicked in but it was running very well

Wow, I can't believe I missed this post,...I have a MDS .48, it's dead, the only advise I could give you is never run fully syntetic lube fuel through it. I't will die. Mine has a streached crank because I switched to fully syn fuel, I even richened it up for the first flight, and it was it's last. MDS stands for "most die suddenly", and it's the truth, but it sure had gobs of power running on 10% nitro, byron fuel that is. If it were me, I'd buy a supertigre for cheap and never look back. Even my cheap chineese made tigre runs great with almost no break-in time.

mds = mutiple dead sticks
btw this thread is from 2005[X(]

Very old thread but I must say, every one is wrong, MDS stands for Many Dead Sticks!!!! I still have a couple of them, one .58 is almost new in the box. I had one .68 that ran pretty good, when they ran they were power houses!! What I did find out {too late} was they liked FAI fuel better then what we run here in the states. I was using 15% and they hated it. When I tried 5% they ran better, a lot better. My bad, if I would have sat down and given it some thought I would have come up with the easy answer, they are made in Russia and nitro cost too much to be using so give some FAI a try. It still didn't mater much, the engines castings were so bad they broke just from the mufflers weight and vibration. If I make up a new run in stand I may get the ones I still have running again and see if anyone wants them. The .68s were for some reason better then the .58s?? Both running and castings.