Horizon Hobby Dumps MDS Line?
07-04-2004, 04:21 PM
#51
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RE: Horizon Hobby Dumps MDS Line?
Ok I have learned nore about the MDS40 in this post than I have raading the manual. I too would like to give the engine a chance. I sent the first back to Horizon when my instructor could not keep it running on my XtraEasy trainer. I few a KB 40 on the trainer that a friend gave me and I never had any problem. I learned to fly on the Xtra and the KB engine combo. I recently took the replacemnt MDS 40 out of the box and am trying to get to run.
I now have learned about the fuel (5%) and the long reach idle bar. Please tell me how to run it in on the test stand. Please be specific as to time on and off, how long rich and how long lean, what RPM, what prop, how many clicks should I move the needle each time, and how do I set up the low side? Also I guess that I have a stupid ear because I cannot tell the "2 cycle and 4 cycle break" because the engine either quits from too rich or too lean.
Thanks all
I now have learned about the fuel (5%) and the long reach idle bar. Please tell me how to run it in on the test stand. Please be specific as to time on and off, how long rich and how long lean, what RPM, what prop, how many clicks should I move the needle each time, and how do I set up the low side? Also I guess that I have a stupid ear because I cannot tell the "2 cycle and 4 cycle break" because the engine either quits from too rich or too lean.
Thanks all
08-15-2004, 09:31 PM
#52
RE: Horizon Hobby Dumps MDS Line?
I have a MDS 1.48 with the newer carb (third one from Horizon) and now it runs great. It probably did take about a gallon of fuel to finally break it in. It always starts on the first flip and has plenty of power. The carb is a little slow to react and one has to think about throttle in advance. But I am using 15% S&W fuel with a Fox plug, a 16X8 in an UltraSport 1000. Originally, each landing was a deadstick, but now no flameouts
bob walker
bob walker
11-18-2005, 12:40 PM
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RE: Horizon Hobby Dumps MDS Line?
OK guys, I've read three pages of pro's and cons of MDS engine owning and operation and see some good suggestions on the pro side of the issue.
A buddy of mine has a brand new (NIB) MDS 1.48 plus a new Bisson Pitts muffler he'll sell me for $150. Is this a fair price and should I buy it?
Thank you all for the great info.
A buddy of mine has a brand new (NIB) MDS 1.48 plus a new Bisson Pitts muffler he'll sell me for $150. Is this a fair price and should I buy it?
Thank you all for the great info.
11-18-2005, 04:26 PM
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RE: Horizon Hobby Dumps MDS Line?
Gee's Homebrew, then how do you explain the engine leaking fuel from just about every joint and seal?
That was my biggest gripe about MDS engines when I tried them out. (MDS Blackheads)
Please don't tell me that I was tuning the 3 that I had, incorrectly. How could one tune a motor that constantly leaked fuel out in torrants -- and air in ?
My idiosyncratic Fox motors were a dream to sort out, compared to these 3 Russians. My bad experiences with MDS turned me right off the brand.
I'm glad, for MDS users who came after me, that they apparently got this all sorted out in the silver head line. I genuinely like to see and hear of people having fun when flying.
But down here, the damage had been done and the Aust distributor eventually gave 'em away. I haven't seen one advertised in a Hobbyshop or a local RC mag downunder for ages now.
In some ways, a pity, as the brands available down in this part of the world are getting less and less. Magnum have become virtually impossible to get, (distributor problems) Irvine have gone and Enya overpriced.
So down here it's really a choice of the 4 main Asian brands. TT., OS., ST., GMS or VMAX. (which is made by GMS anyway)
Rossi are hard to come by and unless one has a good contact, as I do, so are MVVS.
I've got to go to the USA for Fox, but I accept that.
That was my biggest gripe about MDS engines when I tried them out. (MDS Blackheads)
Please don't tell me that I was tuning the 3 that I had, incorrectly. How could one tune a motor that constantly leaked fuel out in torrants -- and air in ?
My idiosyncratic Fox motors were a dream to sort out, compared to these 3 Russians. My bad experiences with MDS turned me right off the brand.
I'm glad, for MDS users who came after me, that they apparently got this all sorted out in the silver head line. I genuinely like to see and hear of people having fun when flying.
But down here, the damage had been done and the Aust distributor eventually gave 'em away. I haven't seen one advertised in a Hobbyshop or a local RC mag downunder for ages now.
In some ways, a pity, as the brands available down in this part of the world are getting less and less. Magnum have become virtually impossible to get, (distributor problems) Irvine have gone and Enya overpriced.
So down here it's really a choice of the 4 main Asian brands. TT., OS., ST., GMS or VMAX. (which is made by GMS anyway)
Rossi are hard to come by and unless one has a good contact, as I do, so are MVVS.
I've got to go to the USA for Fox, but I accept that.
11-18-2005, 07:26 PM
#57
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RE: Horizon Hobby Dumps MDS Line?
ORIGINAL: sladerwilson
I must admit - I bought the .40 MDS for a Trainer Kit from Horizon 2 years ago and had nothing but troubles. Two experienced trainers at my local field spent the better part of the summer trying to get the MDS to run properly... I spent more time on the ground than in the air. I swapped the MDS out for an O.S. and never looked back. Not bashing MDS... several of the guys at our field say the same thing I am hearing on this thread.... some love MDS others hate em. My experience wasn't a good one - thus I don't use them anymore. Just my 2 cents.
I must admit - I bought the .40 MDS for a Trainer Kit from Horizon 2 years ago and had nothing but troubles. Two experienced trainers at my local field spent the better part of the summer trying to get the MDS to run properly... I spent more time on the ground than in the air. I swapped the MDS out for an O.S. and never looked back. Not bashing MDS... several of the guys at our field say the same thing I am hearing on this thread.... some love MDS others hate em. My experience wasn't a good one - thus I don't use them anymore. Just my 2 cents.
From what I can tell, the MDS engines were set up for 0%-5% nitro fuel, the same as Rossi, Webra, Irvine and other European engines. Running 15% or more nitro in one of these engines on a hot, humid summer day will lead to overheating and deadsticking. Add to that a larger than normal prop in order to quiet down the engine and you will have a very unhappy customer.
ASP's early engines were plagued with the same problems because of their high compression ratios, as was the Saito 1.50 four-stroke in its initial form. I have owned a dozen ASP engines and have never had a problem with any of them. Why people insist upon using more than 5% nitro is beyond me, if they are not willing to adjust the engine's compression ratio/prop load.
11-18-2005, 07:28 PM
#58
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RE: Horizon Hobby Dumps MDS Line?
ORIGINAL: Boomstriker
That's what I use to think HOMEBREWER-- till I bought a couple MDS's and learned the hard way.
I also assumed everything bad I heard about MDS was from guys that didn't have a clue or didn't have any engine experience. I've never had an engine I couldn't make run perfectly, but both MDS .58s I had as well as any I've seen at the field were nothing but trouble. Overheating, detonating and deadsticking was the norm.
Adding head shims or using 5% nitro helped, but power dropped to little better than that of a good .46.
If the manual says up to 15% nitro, then you should be able to run 15% without problems.
Mine wouldn't run on the plug it came with, the H9 that Horizon recommended, nor any A3, #8 or enya that works perfectly well in any good sport engine.
I know, I know. "The Fox idle bar is the cure-all plug". Well, just like the one it came with, it burned it in short order and was no improvement so I never bought another. Maybe, after a gallon of fuel it wasn't broke-in yet. I seem to remember the book saying a couple tanks. And if the Fox plug is so good for the MDS, why is it not recommended in the manual or by Horizon?
My observations were that the comp. ratio was way too high for 15% nitro and the carbs, both old and new versions, are way too rich in the midrange causing load-up and flame-outs. With 5% nitro, the power is disappointing at best and the transition is very slow.
Obviously, some of us have figured out the key and have gotten them to run better by following some simple rules, but if the instructions were to specify this and recommend no more than 5% nitro, supply extra shims, recommend a 1 gallon break-in and only a fox idle bar, maybe some of the others would have better luck getting them to run reliably.
I bought my .58s for 3D style of flying, which requires a reliable, powerful engine that will hold a needle setting, run consistently full to empty and in any attitude and have instant transition from any throttle. I can't have an engine that's going to flame-out in a 10' hover or be any less than 100% reliable.
Maybe if I flew straight and level 300' up at 3/4 throttle for a whole tank, or had it on a plane that collected more dust than bugs or wanted to raise my engine collection another count, I might be able to deal with all the DS and a cheap, under-powered MDS might fit the bill.
Most of us are in this hobby for fun. For me, it's not much fun if you constantly have to fiddle with a finicky engine that's not reliable.
Spending countless hours experimenting with different fuels, glowplugs, compression ratios, needle settings/tapers, tank levels, props etc. to get an engine to run reliably might be a huge 'sense of accomplishment' or even fun for a small percentage of guys with the time and patients.
The problem is, 99% of the guys that purchase an engine want, and expect it to run perfect right out of the box when they follow the instructions.
I'm glad some of you have also figured out the secrets to keeping an MDS running and are happy with them, but please don't further insult the majority of guys who regret their purchasing an MDS by insinuating that they are 'bad tuners' when most are just following the 'bad' instructions for a marginal engine.
Kirk
That's what I use to think HOMEBREWER-- till I bought a couple MDS's and learned the hard way.
I also assumed everything bad I heard about MDS was from guys that didn't have a clue or didn't have any engine experience. I've never had an engine I couldn't make run perfectly, but both MDS .58s I had as well as any I've seen at the field were nothing but trouble. Overheating, detonating and deadsticking was the norm.
Adding head shims or using 5% nitro helped, but power dropped to little better than that of a good .46.
If the manual says up to 15% nitro, then you should be able to run 15% without problems.
Mine wouldn't run on the plug it came with, the H9 that Horizon recommended, nor any A3, #8 or enya that works perfectly well in any good sport engine.
I know, I know. "The Fox idle bar is the cure-all plug". Well, just like the one it came with, it burned it in short order and was no improvement so I never bought another. Maybe, after a gallon of fuel it wasn't broke-in yet. I seem to remember the book saying a couple tanks. And if the Fox plug is so good for the MDS, why is it not recommended in the manual or by Horizon?
My observations were that the comp. ratio was way too high for 15% nitro and the carbs, both old and new versions, are way too rich in the midrange causing load-up and flame-outs. With 5% nitro, the power is disappointing at best and the transition is very slow.
Obviously, some of us have figured out the key and have gotten them to run better by following some simple rules, but if the instructions were to specify this and recommend no more than 5% nitro, supply extra shims, recommend a 1 gallon break-in and only a fox idle bar, maybe some of the others would have better luck getting them to run reliably.
I bought my .58s for 3D style of flying, which requires a reliable, powerful engine that will hold a needle setting, run consistently full to empty and in any attitude and have instant transition from any throttle. I can't have an engine that's going to flame-out in a 10' hover or be any less than 100% reliable.
Maybe if I flew straight and level 300' up at 3/4 throttle for a whole tank, or had it on a plane that collected more dust than bugs or wanted to raise my engine collection another count, I might be able to deal with all the DS and a cheap, under-powered MDS might fit the bill.
Most of us are in this hobby for fun. For me, it's not much fun if you constantly have to fiddle with a finicky engine that's not reliable.
Spending countless hours experimenting with different fuels, glowplugs, compression ratios, needle settings/tapers, tank levels, props etc. to get an engine to run reliably might be a huge 'sense of accomplishment' or even fun for a small percentage of guys with the time and patients.
The problem is, 99% of the guys that purchase an engine want, and expect it to run perfect right out of the box when they follow the instructions.
I'm glad some of you have also figured out the secrets to keeping an MDS running and are happy with them, but please don't further insult the majority of guys who regret their purchasing an MDS by insinuating that they are 'bad tuners' when most are just following the 'bad' instructions for a marginal engine.
Kirk
You have to realize that those manuals are ususally written by marketing folks, not engineers. They want to sell as many engines as possible, even if they have to tell you that it is your fault you are having problems when they know darned well it isn't your fault.
I'm not saying that your .58's didn't have real problems. You were there and I wasn't.
11-18-2005, 07:30 PM
#59
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RE: Horizon Hobby Dumps MDS Line?
ORIGINAL: Stripes
Chief Aircraft is currently selling the MDS .40FS PRO for $49 so I bought two. I always take new engines apart just to be sure and the first one had metal shavings around the rear bearing and what looked like metal dust in there too. The fit of that first engine was acceptable. The second engine was spotlessly clean and had an exceptionally fine fit however on this engine the barrel of the carburetor did not line up correctly when full open. It took about a half hour to correct that.
Had the first engine been run without cleaning I am sure it would have been a disappointing engine for its' entire life. The second would have been just wonderful.
I have several MDS .28s and use them in club level slow quickie with good results but each of them was carefully examined before running.
Chief Aircraft is currently selling the MDS .40FS PRO for $49 so I bought two. I always take new engines apart just to be sure and the first one had metal shavings around the rear bearing and what looked like metal dust in there too. The fit of that first engine was acceptable. The second engine was spotlessly clean and had an exceptionally fine fit however on this engine the barrel of the carburetor did not line up correctly when full open. It took about a half hour to correct that.
Had the first engine been run without cleaning I am sure it would have been a disappointing engine for its' entire life. The second would have been just wonderful.
I have several MDS .28s and use them in club level slow quickie with good results but each of them was carefully examined before running.
If I were looking for inexpensive .40 sized engines, I would have bought the Super Tigre GS-40. That is a stellar engine for the money.
Then again, I bought two ST .34 ringed engines for my Twinstar. Afterwards I realized that I could have bought two GS-40s for $20 less total price. Doh!
11-19-2005, 01:15 AM
#61
RE: Horizon Hobby Dumps MDS Line?
I have a question about MDS engines on Xtra Easy 2 trainers. When did Hangar 9 use those? I didn't realize the trainer had been around that long. Well, I have one that I bought from a guy so I'm curious. Mine came with the .45 Evolution training system engine. I think he bought it in late 2003 or early 2004. It's not a bad trainer if you beef up the main gear, cut a hatch so you can reinforce the firewall, and fuel proof it. Kinda tough trainer after that.
11-19-2005, 08:31 AM
#62
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RE: Horizon Hobby Dumps MDS Line?
Barry, I had an Extra Easy about 6 years ago, it came with the MDS .40, the MDS was a little slow to spool up when doing a slow fly by. I put one of my ST .51s on the Extra Easy and went to work on the MDS on the bench. I put a Fox Miracle plug in it and about an hours time on the bench then re-mounted it on the EE. I flew it about three years and sold to a friend who still flies it. He learned to fly with it. Fox 5% nitro fuel with 20% 50/50 lube was and is still used by me exclusively in two strokes. I also changed to a Graupner 11x5, in my mind a 10x6 is a .30 sized prop in modern engines.
11-19-2005, 08:00 PM
#63
RE: Horizon Hobby Dumps MDS Line?
hobbsy,
I wasn't aware that they had been around that long. I think the Evo is the third engine on that trainer. The .45 is one great little engine.
You mentioned breaking an engine in with W8YE. He helped me finish breaking in my Saito .72 when it was having problems. I guess you know that he is back home and it would be nice for him to go flying with us tomorrow if he were back down here.
I wasn't aware that they had been around that long. I think the Evo is the third engine on that trainer. The .45 is one great little engine.
You mentioned breaking an engine in with W8YE. He helped me finish breaking in my Saito .72 when it was having problems. I guess you know that he is back home and it would be nice for him to go flying with us tomorrow if he were back down here.
11-21-2005, 07:12 PM
#64
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RE: Horizon Hobby Dumps MDS Line?
Club trainer Extra Easy with MDS engine. After 4 or 5 years of MDS, another club member donated a new OS 46LA to the plane. Problem solved.
11-21-2005, 09:02 PM
#65
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RE: Horizon Hobby Dumps MDS Line?
ORIGINAL: Ed Cregger
Why people insist upon using more than 5% nitro is beyond me, if they are not willing to adjust the engine's compression ratio/prop load.
Why people insist upon using more than 5% nitro is beyond me, if they are not willing to adjust the engine's compression ratio/prop load.
03-27-2007, 02:38 PM
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RE: Horizon Hobby Dumps MDS Line?
I picked up a second hand model with a MDS58 the other day but no instructions.
Does anyone have a link to tuning the MDS etc?
Seems to be rich on the low end, coughs and splutters etc etc,,,,,please help..
Does anyone have a link to tuning the MDS etc?
Seems to be rich on the low end, coughs and splutters etc etc,,,,,please help..
03-27-2007, 05:34 PM
#69
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RE: Horizon Hobby Dumps MDS Line?
Hey I have a n MDS 68 that sat in storage all winter. It WILL NOT RUN! I cleaned the carb (it s a c2) and new glowplug, and nothing.If i squirt some fule into the carb it will blip to life. So my dilemma, do I fix it or scrap it? Im leaning toward scrapping it, get a few bucks for it and go OS or Magnum. What are the optimal low speed settings? and high speed setings for this engime? I forget. Ill take offers, and the right one can have it.
03-27-2007, 06:22 PM
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RE: Horizon Hobby Dumps MDS Line?
With the carb at full open set the LS needle a large 1/16th inch from the end of the spraybar and the HS needle at about 3 turns out. Peak the high rpm and then set the LS for best idle and transition. It sounds there is some dried fuel in the carb.
03-29-2007, 12:52 PM
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RE: Horizon Hobby Dumps MDS Line?
ORIGINAL: Stevie334
I picked up a second hand model with a MDS58 the other day but no instructions.
Does anyone have a link to tuning the MDS etc?
Seems to be rich on the low end, coughs and splutters etc etc,,,,,please help..
I picked up a second hand model with a MDS58 the other day but no instructions.
Does anyone have a link to tuning the MDS etc?
Seems to be rich on the low end, coughs and splutters etc etc,,,,,please help..
