Folks,

I have been contemplating the purchase of a 50cc class engine and had narrowed the choices down to either a DA or a BME. During my research I came across this thread, and am left wondering why a company with the stellar reputation that DA has, is yet to find a definitive solution to an apparently common problem, that has been proven to exist for some time now. This particular purchase would be my first venture into the world of gas. An experienced user of gas engines might find this problem a minor nuisance, but as a newbie to gassers, my goal is to purchase a quality, high ended (performance wise) reliable and user friendly engine. Maybe I am being naive in expecting all of those qualities out of one engine, never-less I have done several hours of research on the choices available to me, and had settled on the 2 brands mentioned. After reviewing this thread I believe that for me, as a newbie, that the BME might be the better choice. Just my .02

That's a wise move checking all the info before you buy... But, I've had the BME 50 and had some problems with it (ignition) to the point I changed to DA. I've never had problem one with my DA (with about 15 gallons through her) but I do know of friends that have (mainly ignition). What I can tell you though is I think the DA out performs the BME hands down. So, for whatever it's worth, I think it would be wise to go with the motor that give the best performance. If you have a problem with either engine, just beat the manufacturer up until you/they get it right.

Bummer....

Well I got my DA 50 up and running (sort of). I too am having the same difficulies that the original poster had. Looks Like I just need to fly the crap out of this plane so I can get the majic 5-6 gallons through it.

Has anyone else ben able to fix this issue without the need for 5-6 gallons of fuel?

Guys this is not that big on a problem, I did experence some of this on landing after touch down but after the 4 gallions it now runs perfect. If I had it to do all over again it would be the same DA 50.

Here's what I noticed. You have to pull the trim down quite a bit to get the motor to slow down to land. As soon as it touches down, I beep the throttle trim back up to keep it running.

JBrannon:

What is the status of the two sick DSA50s with the bizarre symptoms you described in your initial post? MustangFan has written (6/7/2004) that his sick engine recovered after burning about 5 to 6 gallons of fuel. Have your friends had similar success? And if so, how many gallons of fuel and what gas/oil ratio did they use? I just discovered that I have one of the sick ones (you have described my engine’s bizarre constellation of symptoms with uncanny accuracy) and am trying to decide how to proceed.

One engine has about 35 flights on it and still does it consistantly. The other engine has less time on it and seldom dies. They are both running 50:1 synthetic

Joe

I commented on this problem early in the year. Well after flying the plane all summer the problem still persists, it stalls on landing and any stopping of forward motion of the plane. I have 2 Da 50 engines the one I picked up at Toledo this year is fine. The problem engine has never quit in the air. I'am getting tired not being able to taxi back to the pits and so are my fellow fliers tired of seeing me out on the field. I have had no answers from DA when I phone! PS believe me it is not the needle settings.

Joe and the others---

I have yet to run my DA-50R so I can't offer any help due to direct experience but I do have a theory.....If your engine is mounted inverted disable the throttle spring on the carb. This will prevent the throttle from trying to close due to spring pressure when the plane is jostled on landing or from an abrupt stop. Don't remove the spring!!! As previously mentioned by another modeler, support the throttle pushrod adequately too. Come to think of it---It would probably be best to disable the spring no matter what position the engine is mounted.

I hope this helps. My DA powered Double Vision is about ready to go....I just need some nice weather.

Kevin

The DA50 I had did this with the spring disconnected. It wasn't until I changed to Amsoil 100:1 and went to the larger Menz 24-8 did this stop.

Just a thought ...

I still must have the low speed needle very lean to keep mine from stalling while taxing and landing.
Every once and a while during last summer, the engine would exhibit the problem, then I would need to adjust the needle.

It has been noted that the needles change their settings due to vibration.

When I adjust, I move the needle in until it will not transition well ( engine will quit when throttled up), then move the needle out a little until the engine will transition OK.

I am also using a small amount of throttle delay ... this seems to help by allowing a slightly lean setting for idle.

... it's been a good running engine after break-in. Considering purchasing another.

Good luck to all !!!

P.S. I have the spring disconnected.

OUCH !!

Just read this thread and scared the bejeezus outta me!

I fly a large P-38 with counter-rotating DA-50's turning 22 X 10 props.

I've got about 2 gallons of fuel through each engine.... 32:1 Lawnboy.

I spent no more than 10 minutes setting both high and low ends, and the engines run like Swiss watches ( very loud Swiss watches )and have never given me any trouble except I'm a little disappointed in rpm (up to 6,700 now).

As you may know, engine-out on on a P-38 is not just an annoyance, it's usually a freakin' disaster! Anything I should do? Or just be glad I didn't get one on the "bad boys," and keep flyin'?


mt

Hey mt:
I don't have an answer for you, but am just very curious how you got them counter rotating? That does mean that they are each turning a different way, correct?

He's not the only one nervous about these threads! I bought two of these engines for a BF110 twin.

I can't afford any deadsticks!

Let's hear from DA in these threads. If you own a single Da50 then you'll probably be ok but if you're using two in a twin then it's not ok.

I fly gassers for the reliability. I didn't expect to see that a gasser has so many issues!

Hopefully, DA is going is chime in here and calm some nerves?

What do you say, DA?

Counter rotating a reed valve 2 stroke is easy, just set the timing 28 degrees on the other side of TDC...
6700 rpm with a 22-10 is disappointing ? Get real, it's only a 50
And..All 22-10 props are NOT created equal..I have 2 22-10s here I guarantee will turn less than that, a PK and an MSC...Either will load an engine down way more than a Mejzlik, Bolly, or APC...Or whatever other prop is out there...Not all props are pitched as advertised

kram,

I've got 2 of the DA50's and flew them all summer. I did have the rod issue, and not a total reliable idle when landing, but I have NEVER had an engine go dead on me in the air, and that's with 40 logged hours them.

RCIGN1:

You're dead on (as always) about the counter-rotation. I know I could get better rpm out of Mejlick 22 X 10's, but am somewhat stuck with Zingers 'cause they're the only ones I can get a pusher that size. Know of any other "higher-end" brands that make pushers in that size?

Nogyro:

What happened with the rod? Both engines? Did you just notice it by turning it over TDC and listening/feeling?

JaredM25:

DA set one engine to counter-rotate at the factory, no extra charge.

mt

kram,

Lower rod bearing on both engines. Broke in with Lawn Boy @ 32:1 then ran Stihl @50:1. I've since switched to Mobil MX2T synthethic after the break in, and will stay at 32:1. The exhaust ports and top of piston are looking much cleaner with no carbon build up with the MX2T. You can feel and hear the rod bearing going out. Rock the tip of the prop back and forth against compression stroke. If the bearing is ok, there will only be 1/64" or so of play at the end of the prop. When the bearing starts to go, the prop movement will increase to 1/8" or so. You will also start to hear a tapping noise while the engine is running or in flight. When mine went, DA went all the way through the motor. If there is even the slightest chance that another part was damaged, they will replace it. Service was quick. No complaints at all.

It seems that not all of the DA-50 Engines have this problem.

If you do have the problem, it will manifest its self when .... (my experience )

1.) The Plane is sitting in a nose high position while idling, then the tail is raised.
2.) Sudden Stops or turns.
3.) Plane descends a grade.

I never had a problem in the air, but I kept the idle on the high side (high / low on a switch).

Since I even had a higher than normal idle (low switch setting) landing was a little bit of a problem ... so I went to a lower pitch prop ( 22 X 8 ).

The best "Guess" of the cause I have heard is:

The fuel is pooling in front of the carburetor spacer, then when the nose is raised etc., the fuel flows down into the inverted cylinder past the rings and chokes the engine. After the rings fully seat ( 5 to 6 gallons of gas ), the problem goes away.

Maybe this is why some people have the problem, some don't .... Inverted vs upright vs side mounting. Never did a survey.

A very lean needle and throttle delay helped me through this period.

Good Luck .... it's a good engine after break-in.

I had that problem at first. Now after 4 gals my DA 50 is the best running engine.

it's a shame but DA doesn't wish to talk about the problem. My guess is they don't have a solution yet. If they did, you would think they would say something.

john

Anybody ever think maybe the current practice of using a large diameter prop and loading the engine down might be part of the problem ? Like running up a big hill in your car in high gear--it WILL do it, but why ? The auto transmission shifts down to keep the engine in the power band..Running a 24-8 on a 50cc engine is kinda the same..That little pressed in roller bearing on the big end of the rod is working very hard...I haven't seen a mention of where the max torque is on a DA 50, so maybe I'm all wet...OR the bearing is too small..OR the aluminum rod doesn't hold the thin shell of the bearing tight enough, hence the new steel rod...
If they would use a case hardened steel rod with a chain saw type roller bearing running on a crank pin with a hard enough surface there would be no problem..But that would cost more...And there would be the problem of the bearing sliding out of the rod..OPS did this with their 30..They used a washer held on the end of the crank pin with a left hand thread screw..How do I know ? Tried to unscrew one..
Maybe DA should ask Brison how they did it--theirs works....

Hi
I had just ordered a DA 50 and i found this thread. What joy! RCING 1 Brings up a valid point Prop size I have never ran a Gas plane but have worked with motors of all types all my life and Know that taking a high performance engine and expecting it to fool proof Is never the case Also the miss use of synthetics can gum up the works. Im curious as to how many of the people here are using the amsoil rated for 100:1 and mixing it richer than spec?
I know this is a different engine but if i run a large prop on a glow 4 stroke it runs good if its plastic if i run the same size and pitch prop in a wood prop it pings and knocks like an old Pinto on bad gas.
How many of you with the problem are breaking your engine in on a 22X10 or larger? Isnt the break in proses geared to get the motor to spin up to 7000 RPM and stay cool in the proses? Isnt a 22X8 the better choice regardless of flight performance. What props have any of you tried that produce that kind of RPM? I know I have always driven any engine I have ever built like it was going to be used when i turned it loose to the masses. My experience is in construction and fleet repair. I know not one of my engines was ever babied after i finished rebuilding it Granted i get the first run around the block but always turned the engine over the next day to the cowboy mentality that was employed at the time. I have had 3 OS 46 ax motors the one that started to chew up the crank was the one I babied the ones i have that fly well are the ones i started up set the mix and sent up and flew. I dont think i would ever bench run a engine. When I get my DA I will follow the recommendations from DA as close as I can But till i read it from the horses mouth I have to rely on the input from other users. I wonder how close the 2 agree?

Well, I ordered a DA-50R that should get shipped in about two days. When I talked to Brian at DA two weeks ago, he indicated that the 23x8 Mezjlik I ordered with it would be great to break it in with, as well as fly.

Mine should be in today and I have a MSC 22-8 ready for it..Will break in with Lawnboy Ashless 32-1 then Amsoil 100-1