Boomstriker

Both of mine ran OK on the test stand too, but the stand only simulates level and upright flying. Even an MDS can be tuned for reliable running when fuel pressure is constant.
In a hover or any type of 3D is when a finicky engine is going to have problems because the fuel deliver is subject to gravity and extra G forces affecting it, and this temperamentalness is only compounded as the tank goes from full to empty.

When you get the high needle rich enough to pull from hover at full throttle without overheating and detonating, then they get very rich in the mid and will flame-out if held there very long. Leaning the top anymore puts it in the dangerous lean condition when nose up. The only way to combat this is to lean the low as much as possible to help with the mid.

The only way I could drop-in from any altitude was at a idle, because it would load-up REALLY bad when nose down and with any throttle applied. If not, I had to rev it up every couple seconds on the way down to keep it cleaned out or it was sure to die when I went to add power. This makes landing, slow flybys or any 3D maneuvers very risky.

IMO, using an MDS in an overpowered 3D or funfly is just asking for trouble.

As I've said before, maybe in straight, level and upright flight on an under powered plane where it's near wide open most of the time, maybe you could consider it a reliable engine.
I have never seen anyone using an MDS reliably for 3D or aerobatics, on a heli or for any type of competition. Aside from a few that seem to want them for their collection, I've only seen trouble and disappointment, first hand and on the forums.
If I bought every MDS engine that's been a PITA in someone else's plane and ran on my stand, just think how big MY collection would be.

Sport_Pilot

Boomstriker.
It is possible to make a test stand that is tippable, or even rotate to full inverted. As for as how an engine behaves flying VS on a test stand, this is just how well it is set up. I don't know of anything an OS or Webra has over an MDS in this regard, except for the pumped versions.

Hobbsy

My Feedback: (102)

I too disagree with Booms characterization.

Sport_Pilot

I have not owned an MDS but being of Russian manufacture I would expect and I hear that they are fairly high compression ratio engines. This means low nitro and cold plugs. If you do not use low nitro or cold plugs then I would expect overheating and detonating. Please don't knock engines because of your ignorance!

DrDeath

My Feedback: (3)

I am not a big advocate of MDS but I do not hate hate them. I had an Extra Easy 2 to learn how to fly on. The engine was the .40 size one. I had troubles initially, but someone suggested going to an idle bar. After that the engine ran reliably. I can't say that the power was outstanding though. I have since replaced that engine with a TT .46.

I say all of this because the engines can be tempramental, but they do run reliably if you do the following.

1) IDLE BAR
2) Break in engine well
3) IDLE BAR

and finally

4) Did I say use an IDLE BAR

Hope this helps

Lee

changed

I think I'll mount mine on a plaque and use it for the worst crash award. I just can't see wasting hours of fiddling and gallons of fuel to get it to just run ok. I'd rather be flying with an engine that is made to run! With all the fuel I have run through it I could have paid the extra 40$ and bought a nice engine! Thanks guys for showing me the way.

Sport_Pilot

Squint,
I bet homebrewer runs almost as much fuel through an OS before flying it. Most people at my field don't run but maybe an extra tank or two more than the OS. No complaints except you must use the pinch test, and they get stronger and easier to tune after they have run an hour or so. Homebrewer just likes to bench run. I think he and Hobssy get together and crank up a bunch of engines in a huge circle now and then.

Hobbsy

My Feedback: (102)

Well, I'm a minimum break in kinda guy, any engine can be broken in after getting it's set up on the test stand. Homebrewer and I have never run engines together but W8YE and I have on a couple of occassions.

wrob

All this talk about MDS engines makes me think I need to go fly mine .

Homebrewer

My Feedback: (8)

Nope, I run 1-2 tanks on my OS engines because the CHEAP nickel plated liner is softer and easier to break in.

Too many of you are too impatient and many of you have never had a real ABC engine to deal with before. The advantages of the MDS engine is that it will outlive any OS engine out there. One of my MDS 68s is about 5 years old and has close to 300 hours on it. It is only off about 200-300 rpm from when it was new and still pulls strong.

The advice I gave on the bench break in was intended for folks who may not have a properly setup airplane and the bench breakin would help rule that out.

I personally don't give a rats butt whether the entire world hates the MDS line. The more of you that spread its supposed bad reputation, the cheaper I can buy them from ya all. So, please continue bashing the MDS line so I can stock up on more of their engines for cheap!

Thank you and have a good day.

Andy

PS MDS engines suck......please rid yourself of any you may own before it is too late.

Thumper1

I had one, a 40. Nothing to write home in the way of power. A couple of guys in our group ran the 1.48. Got lots of practice landing dead stick. Tried REAL hard to unload them. No takers. The engine acquired a reputation for runibility problems and very few were bought recently.
Bill

Sport_Pilot

Didn't the 1.48 have some sort of carb problem that was resolved a year or two ago?

Warjet

My Feedback: (327)

Along with the longer than expected break-in running required, the machined carbs MDS made were of inconsistent quality, leaked air around the barrel, causing lean-outs and dead sticks at just the right times. The latest carbs (C2) are much better, and the carb off the 2.18 not only works great, but fits the big ST's, Webra's, and anything that the OS 7D carb fits.

dennis

My Feedback: (90)

I'm not going to comment on MDS one way or the other or OS motors for that matter. However if you want to talk about long lasting motors there are only a few glows that fill that nitche. one is the Fox 35 and the other is the Enya35.Both of these are iron and steel and will /have lasted for 50 years of running. I know I have a few.
Dennis

Hobbsy

My Feedback: (102)

I have accumulated several of the MDS C1 carbs and the clearence around the barrel is the same as any other MFG.s carb, if there ever was a problem with leaking, it was through the pinch bolt assembly which they cured by putting an O ring on the bottom of the carb neck. One of the C1 carbs now resides on my old Webra .91 where it works perfectly, a previous owner had butchered the stock Webra carb.

Sport_Pilot

So.....Who is going to carry MDS now?

mnrcaerobat

My Feedback: (197)

I have had three MDS and think they all are great. I recently bought a MDS 40 for cheap. I heard they are terrible and wanted to see for my self. It is a great running motor. It even has the old carb and was never ran.

I ran it for about 5 min. slightly rich twice. Then adjusted both needles. I set the high side around 12,500 to 12,600. My max RPM was 12,900 with a 10x6 prop. Next I checked the transition, and it was horrible. I tried opening it more and that got worse. I closed it all of the way and opened it one turn, and it now transitions to full RPM instantly without hesitation. I am running Wildcat fuel 15 nitro 18 total synthetic oil. Glow plug is a OS 3.

My muffler is a Mousse Can Pipe that I made following directions from http://www.spadtothebone.com/SPAD/Mufflers/

For thin wall pipe, I used a lawn chair. The outlet hole on my MCP is 1/4".

This muffler also improved the performance of my MDS 48 transition.

dennis

My Feedback: (90)

As far as I can find out. Horizon Hobbies has not dropped the MDS line but is no longer the propriatery supplier of these motors. I would imagine that MDS wants to widen their distribution outlets. Rest easy MDS lovers the motors arn't going away. Dennis

bryfly

I have had all of the problems listed above--deadsticks-overheating--but finally fiqured it out--I wish they would have just mentioned to run FAI fuel in them--do we really need nitro?--so but the cheap FAI fuel and your MDS will run fine and might just surprise you with the power--please folks no nitro its expensive!!!

Kimhoff

My Feedback: (22)

Pull the needles from your carb and inspect them closely under a high powered magnifing glass. I bet you will find that they nicks and flat spots in them. Polish these out with fine wet/dry and go fly.

Rcpilot

My Feedback: (78)

I noticed that Horizon was constantly out of MDS engines recently. No big deal though, because I'll never buy another one of those pieces of horsecrap.[:'(]

Had a .68 and 2 of the 148 size engines. All were pieces of junk.

I'm like the rest of you guys. The darn thing should run right if you set it up correctly.

I had an OS 61FX engine on a 4*60. Pulled it off and mounted the MDS 68 on the same engine mount. Didn't change a single thing on the plane. Thing ran like total horsecrap. Yeah, yeah, yeah, yeah, I did a proper break in on it and was using low nitro fuel, 5%. Yadda, yadda, yadda, it was a piece of junk.

The 148 engines were junk too. I had the "newer, more better" carb on both of them. Didn't help any. Had them BOTH on the test stand for more than a gallon of fuel. Omega (pink) 5% fuel. Nothing wrong with that stuff. Mounted the first one on my BRAND NEW, just finished building it after 6 months, Lanier Laser 200, 25% plane, Plane takes off after about 150' and climbs to 30' above the runway- engine deadsticks and I crash the plane. Totally destroyed my brand new plane. About $1200 invested in the plane. Was I pissed off-----------------YEAH!!!!!!!!

Second MDS 148 was on a H9 Cap 232 25%. Same meticulous break in with OVER a gallon of 5% fuel. 1st flight out- it ran like crap for 5 minutes, so I landed it and took it home. Took the engine off the plane and slapped it back on the stand. Finished out a 2nd gallon of the 5% Omega fuel. So now it has 2 gallons of fuel through it on the stand and 1 tank through it in the air. Lost my plane on the 2nd flight about a weeek later. Engine deadsticked on takeoff- about 40' above the runway. About $1000 invested in the plane. Was I pissed off----------------------YEAH!!!!!!!!!!!!!!!!!!!!!!!!!!!

Yup- MDS engines suck, in my book. You'll never see another one of those pieces of SH*T on any of my planes.

Sorry- did I sugarcoat anything?

Hobbsy

My Feedback: (102)

No, but you didn't sway anybody either. I just bought my third 1.48 and second 2.18 and they will be great engines too.

Tired Old Man

My Feedback: (1)

For those interested, MDS is out of business based on information I received from a distributor. I don't think anybody will be carrying the MDS line any longer. If you want to get spare parts, get with Horizon to see what they have left in inventory.

trev13

Is there anyone out there who knows if Horizon will still honor their three year warranty.I would guess that so long as the warranty is in effect they would have to supply parts,or else they would have to replace each defect with a comparable engine. This could get pretty expensive considering that a written warranty is a legal contract.

w8ye

My Feedback: (16)

They still have most of the parts. They still have ASP parts and they dumped ASP nearly four years ago.

Jim