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-   -   MLD-28 gasoline engine (https://www.rcuniverse.com/forum/gas-engines-142/7631608-mld-28-gasoline-engine.html)

e-fly 12-30-2012 09:18 PM

RE: MLD-28 gasoline engine
 
Hi
We are ready to send CDI to US, you can contact to replacement, soon I will tell you the specific location at here.

AA5BY 12-31-2012 01:53 PM

RE: MLD-28 gasoline engine
 
Jimeni... hope the New Year is a good one for you. Can we compare a note or two on the MLD-35? Mine is installed inverted and richens when the plane inverts. I get a little more residue from it than any other gasser and I'm thinking most of it comes from those inverted periods where it is obvious that combustion is not good.

The low end is as lean as it will go and transition ok and the high end is near or at peak rpm. Running a Vess 20A on a 16.5lb plane and IIRC, it runs at about 7500. Using standard octane probably with the 10% blend and 40:1 Pennzoil 2 stroke outdoor. I'm basically happy with the oil as shown in a rebuild after a crash and bent crank of a Zenoah G-20... the inside looked great and the engine had over 600 flights on it.

Any ideas about why the MLD-35 runs rich flying inverted? I'd also say it is slightly richer mid range than most of my other gassers. I really think the only adjustment option left is the float needle or a carb change but the issue is not serious enough to me for a carb change.

Also pertinent is that it has always been this way so its not a recent air leak kind of thing or carb debris thing. It has about 120 flights on it now.

As to the MLD-35, I could not ask for an easier starting engine either cold or warm and in the 120 flights, no dead sticks.

Any ideas?

airborne2.4 12-31-2012 03:05 PM

RE: MLD-28 gasoline engine
 
Happy New Year to all!!

Jim, did you strap your MLD 35 on the Fliton Extra 330?

Hopefully I'll have an opportunity to put my 28 in the air some time this week. Its been in the hangar for a while.

Jimeni 12-31-2012 05:21 PM

RE: MLD-28 gasoline engine
 
Happy new year to all.

Yes Airborne, it is on the Fliton, and WOW. It is now a giant foamy!!

AA5BY, if we were to compare notes, I would note verbatim what you described. Vess 20A, Stihl Ultra 50:1. I am still working on the leaning inverted. At 1st I thought maybe my clunk came off, but it did not. I tried a vess 18x6, but the high end wouldn't lean enough to keep rpm's down, and had to limit T servo travel. So 18x6 is just not enough prop. I got a Vess 19A but have not installed it yet. I think it will be perfect. 20A is good too though, I had 7500 as well. Not going to help the inverted issue I don't believe. I have pretty much eliminated fuel supply issues, so I guess its time to look at airflow. I have not changed the cowl cut out from the 28, but as you know that's a side carb. I had no issues with the 28. It only happens when inverted for an extended period. I may look at trying to upgrade the carb also. The high needle, on mine at least, has very little authority. My carb aft edge is just through the firewall, so I am really not expecting it to be airflow, but you never know. I did switch to AMSoil Sabre at 100:1. Got a hair more power, less residue, but not much relief on inverted. It was a little better inverted at 100:1, but still an issue. I think the engine would die if I stayed inverted, didn't want to press it to see.

Jimeni 12-31-2012 05:37 PM

RE: MLD-28 gasoline engine
 
E-fly, I don't know if this helps or not, but on the earlier ignitions, I personally did not see any bad CDI's, the issues were all in the connector pins. They were over crimped, breaking the wires causing very short lived connections. These were all in the sensor lead connectors, and plug lead shielding to boot solders. The solder was a less frequent issue, and caused the engines to not run at all. The sensor connector would lead you to believe it was tuning until the connection got bad enough to not run at all. With good connections, these are great CDI's. I removed all the connectors on my melody ignitions and direct soldered the wires, and have had no trouble since. I have SPE 26, 43, MLD 28, and 35. I love these engines!!!

airborne2.4 01-01-2013 04:35 AM

RE: MLD-28 gasoline engine
 
A giant foamy!! Now that's what I'm talking about:D

AA5BY 01-01-2013 04:59 AM

RE: MLD-28 gasoline engine
 
Jimeni... Thanks for the response which confirms the inverted issue to probably a general one.

First, I've flown mine circuits inverted with no hint of dieing. I confirm what you said, that the HS needle action is not typical, ie it doesn't continue to lean out the engine.

There is a plausible explanation of what is happening in that the metering diaphragm is on the bottom of the carb when the engine is mounted inverted. It's conceivable that its weight could influence the metering circuit slightly and such makes sense considering that gravity would favor more closure of the metering needle when upright compared to inverted.

I don't know that I'll make a special effort or do so when maintenance is needed on the pump but I've thought of bending the metering arm slightly to favor greater closing and will probably do so.

The engine is in an original design I built last winter. I'll offer a video of the maiden flight for your comparison.

http://www.youtube.com/watch?v=QINu1...ature=youtu.be


e-fly 01-02-2013 07:17 AM

RE: MLD-28 gasoline engine
 
Happy New Year to all!
Hi Jimeni
I am very glad to know that your engines are good. Also I wish every MLD's owner like you happy, I'm trying to solve their problems as soon as possible.

rexbirk 01-03-2013 02:42 PM

RE: MLD-28 gasoline engine
 
e-fly,

I have five of the 28's. Three are the style Cermark sold and two I got from Mile High Rc. The two from Mile High are three bearing and have a different mounting pattern and are slightly longer.

I have had Ignition issues with both types of engines. The ignitions were different styles. Some problems were torn silicone in the plug boot and some were not. The RcExcel ignitions cured all the trouble.

Other than the ignition issues the engines are wonderful performers.<br type="_moz"/>

e-fly 01-04-2013 01:56 AM

RE: MLD-28 gasoline engine
 
Hi
Thank you for telling me in detail.
I have done a lot of work, I had to solve these defects.
As soon as possible there are some new one let you change.
I hope you can accept, and try.



bcchi 01-04-2013 10:05 PM

RE: MLD-28 gasoline engine
 


ORIGINAL: CH Ignitions

Hi Jay,
Thanks for pointing this engine.
If anyone will send me an engine I will try to support this engine also.
Thanks
Adrian
Adrian,be careful,be very careful.About support of any engine.I will talk to you.
BCCHI Grumpy no two.

fly-n-duck 01-21-2013 04:14 PM

RE: MLD-28 gasoline engine
 
I have one of the new motors mld28 and it has a cracked prop shaft been trying for 4 mo with ibcinyourc to get the right shaft and still under the 2 year warranty he give me a old prop shaft ground the washer hub to fit and motor still wont run told me that they wont fix it i dont know why they just cant send me the right one i found out from a nother dealer they dont have extra's from mfg now iam stuck with a Dud be carefull who you bye from.

AA5BY 01-21-2013 05:17 PM

RE: MLD-28 gasoline engine
 
Call Cermark and see if by chance they have another hub. They replaced one for me a while back.


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