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Old Apr 22, 2008, 12:18 AM
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mds 61 engine

please advise me about MDS 61 RC aeroplane engine.About performance,price etc
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Old Apr 22, 2008, 12:20 AM
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waing for reply
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Old Apr 22, 2008, 12:43 AM
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I wouldn't buy one.
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Old Apr 22, 2008, 02:57 AM
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http://www.rcuniverse.com/forum/m_7044163/tm.htm
You will find all you want
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Old Apr 22, 2008, 10:11 AM
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I've only had experience with an MDS 78 and it's a jewel. Slightly outrevs an Enya 80X on the same prop and fuel (zero nitro) and had the lowest idle I've ever seen. One flick starts hot or cold, idle or full throttle.
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Old Jul 20, 2009, 10:52 AM
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MDS 61's

I bought an mds 25r/c abc black head with the old style carb and put it in an artf trainer for my son .......but it just wouldn't run properly every one had ago at setting it up but even if you got it run reasonably well on the ground it would cut out as soon as it was airbourne a very frustrating engine any how that was 8 years ago now and the reason for this story ?
well recently made redundant I was tidying out the garage and found that bloody mds engine the source of so much misery and the only engine I've ever failed to sort out...
so I thought right im gonna find out why it was so bad ! so after a clean I set about running it up and sure enough tilt the modle up engine cut ..run it richer and it's too rich no power when held level poor pickup no real idle etc ...all the old issues.....so first I took a carb from an old merco 61 which had the right venturi size (needed 4 rubber O rings though as the venturi was a bit longer
tried again .....success it ran fine reliable etc infact very powerful and seemed to get better the more I ran it ! started with 1 flick reliable idle amazing.......so what was wrong with the old carb? I set about pulling the carb apart ...all looked ok hmmmm ok i'll just swop bits out till it works ....with various bits from an old box of carb bits ......conclusion main needle and it's seat leaked air in when warm/hot I fitted an SC46 main needle and sleeve (it's a direct fit) and hey presto sorted so now it has the original carb back on it and it's a brilliant little engine very very reliable great power for a 25 and I've even put a tuned pipe on it ....now it's truly one of the best 25's ive owed .......the only thing I would say in setting these engines up (providing the carb works) is they are very heat sensative and must be fully warmed up first and then very small steps to lean out on full throttle 20 seconds wait betwean tweeks etc.
Ive changed the main needle and fuel feed nipple on my mds 61 r/c too and it's a massive improvement even though it sort of worked worked already(used another SC46 needle,sleeve and nipple ) the performance change is massive again i've put a tuned pipe on and WOW it's as good as any other 61r/c ABC side exuast engine ive owned ....no really it is !
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Old Jul 20, 2009, 05:25 PM
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Tokoroa
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I'm sure many here will have seen my MDS61 in action but for the newbies:

Russian MAC/MDS 61 engine (3 min 29 sec)
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Old Jul 21, 2009, 02:08 PM
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USA, TX, Grapevine
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Cool video XJET. That MDS looks to be one heck of an engine for $50 bucks.
it reminds me of the day, some guys talked me into putting a new super whizbang 25 of some type that had just come out on my old small plane to try out. So I did, and the engine sure did have lots of power. I was really impressed. Then the wings folded.
:O

I wonder if one can get parts like connecting rods, cylinders and pistons for it.
i didn't see the engine on the MDS website.
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Old Jul 21, 2009, 05:07 PM
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I notice in the flight in the video, the pilot only throttles back for landing, our experience of MDS engines is that if you do use the throttle during the flight, they tend to stop, hence...

Many
Dead
Sticks

A.
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Old Jul 21, 2009, 05:29 PM
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Quote:
Originally Posted by AndyOne
I notice in the flight in the video, the pilot only throttles back for landing, our experience of MDS engines is that if you do use the throttle during the flight, they tend to stop, hence...

Many
Dead
Sticks

A.

Simply not true.
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Old Jul 21, 2009, 06:00 PM
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I had a couple of MDS engines, one was the old Blackhead one, which wasn't brilliant, but I had a later one, a .40 Pro, which was brilliant. Took a little time to set up, but once running, was spot on and turned an APC 10x6 at 13600 and had a decent idle once it was run in.

It was VERY tight to start with, possibly too much so, but after half a dozen tanks, it settled down. My only complaint was that the seals round the carb and silencer were not brilliant, so it was a bit messy.
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Old Jul 21, 2009, 07:36 PM
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Everett Wa.
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Quote:
Originally Posted by AndyOne
I notice in the flight in the video, the pilot only throttles back for landing, our experience of MDS engines is that if you do use the throttle during the flight, they tend to stop, hence...

Many
Dead
Sticks

A.
Never had a problem with the throttle even in the days when they had Cyrillic letters, sorta like MAC on the case.

If the engine runs well but dead stick after a while at full throttle, this is an indication of over compression. Assuming the engine runs OK just after initial start. Add a few head shims or machine a little more volume into the head. Some have good luck going down in nitro (2%). It is NOT an OS (this is a good thing). Just because one has learned to run an OS doesn't mean that all engines should perform like an OS. I like a to run low nitro and a hot plug in the MDS. Kind of the opposite of the OS.

In conclusion they don't run like an OS, they have more power than the OS of the same size and time frame and they are more durable than the OS on castor oil because of the chrome in the liners.

While they aren't performance engines, they are weak compared to the Rossi and most other Italian engines. They are of higher performance and potential than the OS as a sport engine.

My limited understanding was the "8" series was reworked for the USA market.

Friends don't let friends fly nickel.
Konrad
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Old Jul 21, 2009, 09:54 PM
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Tokoroa
Joined Mar 2004
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Quote:
Originally Posted by AndyOne
I notice in the flight in the video, the pilot only throttles back for landing, our experience of MDS engines is that if you do use the throttle during the flight, they tend to stop, hence...
Nope, I used the throttle a lot -- especially when hovering (yes, it would hover) and I can't recall ever having a deadstick landing.

Just a shame the crank was too weak for the heavy bolly prop I was using and eventually broke.

It's all in a box under my bench and I plan on making a new crankshaft for it.
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Old Jul 21, 2009, 11:04 PM
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Everett Wa.
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Did it break at the front of the inlet port or at the crankshaft web?
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Old Jul 21, 2009, 11:38 PM
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Tokoroa
Joined Mar 2004
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At the edge of the intake port -- they ground a square opening instead of one with rounded corners to relieve the stress. Bad design or manufacturing -- the opening should have been radiused.

The other factor was that the transfer passage through the crankshaft is very big for the diameter of the shaft -- resulting in a paper-thin wall thickness. I'm going to rebuild the front of the engine so I can use a bigger diameter crank and thus gain some thickness in the wall.
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