I have a new DA 50 and it is on the front of a WildHare Edge 540T. I ran it on a test stand to make sure it was O.K. before I mounted it up and it ran like a clock out of the box. I have the Slimline pitts muffler on it and 22x10 prop. Ran 7,200 on the stand. On the plane it only gets 6,800-6,900 and it will not hold a idle at all. I cut the exhaust stacks off about 2-3 inches on both stacks to ge the cowel over them. I figured at the most it may get a tad bit louder. I do not know if it would hold a low idle on the test stand as I did not have a servo controling the throttle, but rather I did with a pushrod. I was just checking for transition and top end RPM then. If you rev it up now and hold it wide open for a little while and then bring it down to idle the RPM hangs up high for 5-7 seconds and then lays down. Probally hangs up at around 4K and decends down to the trim point. This is a synptom of???

I think it is rich on the low end as it hesitates on the transition a little bit. It takes about 2 seconds after the stick is wide open to actually get there. Is that the low end or top end that controls that???? I thought the low end controlled transition. The needles are factory set. I can not get a reliable idle lower than 2,000-2,100 RPM. If I let it set there for over 30 seconds and stick it wide open it will hesitate and quit sometimes. I "think" it is rich, but that is just me thinking. This is my first gas engine, but I am a 20+ year R/C vetran. It acts alot different then it did on the stand. Much easier to start then, but the tank was above the engien and only about 5 inches away and now it is way back and below the engine. Engins isn't hard to start now, it just takes a few flips to get fuel to the engine now. I know the carb is pumped, but I also know that has to affect it too. I know there are a lot of you guys that know what to do, so lets hear it.

Thanks,

Norman Ross Jr.

Norman, something sounds weird. I would call DA. They will know what is up. BTW, I love Fayeteville!!! What a cool town!

Joe

I am definetly going to give DA a call, but I want to hear what many of you guys think it may be. I don't think anything is wrong with the engine, except that it needs tuning.

Norman Ross

Hi Norman.

The tank position in this case will have no effect at all. Don't concern yourself with that.

The idle rpm indicates that either the engine is very rich, or the throttle idle stop screw is set too high and should be backed out a bit. The engine is now in a cowl, and will run warmer, effecting overall operations a little. You may just be ingesting warmer (less oxygen) air into the carb, casuing part of the problem. Also having a spinner will have a small effect, but usually this will add to the rpm.

Without a cowl, bring the engine up to full power while it's being well restrained and peak the high end needle, then back off of it about 1/8 turn or a little less. That should be very close to the high speed throttle setting.

With a new engine, setting the low end needle is not an exact science. It will require changes in settings as the engine breaks in. Go with the manufacturer setting and work back and forth from that 1/2 turn to see what you need to do to get a smooth transition from low to high throttle. Blubbering is too rich. Perform the low end settings below 3,000 rpm.

Cutting the ehhaust stacks on the Slimline will have little effect on the engine. The need for back pressure on a gas engine is very low. Since you have a rear mounted carb, are you certain the the available air intake is adaquate for the engine? And is there ample area (cooling air area squared) for hot air to exhaust from the engine? Both of theses could have an effect.

Good luck,
Pat

All of the running on the plane is with the cowel off and I ran it with a spinner on the stand too. It is quite a bit cooler now then when I ran it on the stand. It was 85-90 and now it is 45-50 degrees.

On the idle screw you just screw it out enough that you can kill the engine with the trim lever correct??? Or do you set it so that at low trim you have the idle and use the choke to kil the engine or some kill switch???

Thanks,

Norman Ross

What are you guys getting for a steady idle??? Out of it when it was new. I know the idle should only improve. It does with all engines. Saito's bigger engines won't idle till you have a gallon of fuel therough them, but do great after you get some fuel through them. What RPM should I look for once I get the top end peaked and slightly backed off and the low end set for a clean response???

Thanks,

Norman Ross Jr.

The idle stop screw can be removed and discarded if will not have any negative impact on the engine operation. On a Walbro carb, I back mine out to where it has no effect on the engine at all and use the the radio to control all the travel and idle functions of the carb linkage. Bringing the idle trim lever down to the bottom on the transmitter should be the "stop engine" position, and anything above the bottom is for various idle positions. That's one of the reasons I, and many others, don't have need of a choke servo.

It sounds an awful lot like you simply have "the fresh engine syndrome", where the darn thing is just to new to operate quite like it should. It won't take very lond at all to get it dialed in and to get used to the differences. One thing to remember though, is that the needle settings on a gas carb are about three times more sensitive as the ones on a glow engine. Small moves can have very large effects.

You're idle RPM will have a lot to due with the prop you use. Larger props provide lower idle RPM. 1,700 to 1,900 RPM will be in the area of where you end up, I would think. The really low idle RPM settings will often reward you with an unreliable throttle up, so be careful in how low you go. Also, it takes about 3 to 5 minutes of running time on a cold engine to get a good steady idle. They really like to be warmed up before they have to go to work.

SilverSurfer you are exactly right about it being new and warming up to run. I called DA today and my hats off to Brian there as I will NEVER consider another brand of engine as long as DA is in bussiness when I buy a gas engine in the 50-100-150 range.

If the engine were only half way decent they would still be worth the price due to the service you get from DA. I told Brian what was going on and he treated me like his best friend and answered every question I had and he actually knew what he was talking about!!!
Everything he said was dead on and when I explained my problems and the synptoms guess what??? He had heard and seen real working gas engines do it before and knew how to correct it!!!!! He took the time to explain how he tunes one and what he listens and looks for on one. I have 20+ years of glow experience, but little gas experience. I was adjusting too much at one time. I am used to running high nitor in my glow engiens and a side benefit of the extra power is the numb needles that are easy to adjust. Gas engine needles are ar least the Da has sensitive needles. I set mine back at the factory specs like I was told to do and the ening fired and ran about 95% perfect from the seting in the manual. Problem 95% solved. I richened the low end a 1/16 and then once more and perfect transition and reliability and very easy to start too.

I sure appreciate all yours guys comments and I have a Pro Zinger 22x10 on the engine and can only get a reliable idel of about 2,300-2,400 RPM. One click lower and if you bump the stick up and down like you do for taxing around it will cough and die sometimes. Bring it up to about 2,400 and it is fine. I have a 24x8 Menz and I put it on and ran it just for a minute to see what it would do and I got 6,500 top end and yeah it idled on down at 1,800, but that is a CHUNK of prop. I will go it it after breaking as DA told me for 3D that is the prop I want and Brian at DA flies it on his Wild Hare Edge 540T. I do not like speed, I like lots of pull and lots of downline braking and the 24x8 Menz will do just that.

After all is said and done now all the thing needs is to have a couple of gallons ran through it to get a 2K idle with existing prop. Thing thing just needs to be flown. I think I can handle that.

Thanks all,

Norman Ross Jr.

Just for the heck of it, how close was I to what DA suggested? BTW, I don't have a DA, but have dealt with Brian and agree that they are great people to do business with. Consider purchasing just one MSC prop the same size as the one Brian suggested and do a comparison. Especially for down line braking. I think you will be pleasantly suprised at the performance, if not at least for the difference in price.

That Pro Zinger is the first thing I would change, though.

THe MSC 22-8 and 23-8 are the best wood props I have ever run on a DA50. JMO!
Glad you got it worked out. Brian and the guys at DA are #1 in my book!

Joe

I know that the Zinger prop is not the best prop, but I only wanted to use it to get to my 24x8 Menz. If I have to I may run a 22x10 Meszlick or however you spell it. I can get a real good deal on one of them. I may sell my 24x8 Menz since I see some people overheating engines with them on a DA 50. DA told that the needle settings absolutely could not be the slightest bit lean with that prop on it. They did say properly set it runs fine with it with no harm as they run it on thier own personal ones all the time as for 3D is the prop they prefer. I am at a toss up I guess.

What it really needs is a tune pipe setup for that prop. Da told me that have a Double Vision and a full length pipe and a 24x8 Meanz and get 7,200 RPM with it!!!! They said it rips the DV around like a rag doll!!! The DV has a pipe tunnel though. Not possible on the my Edge, not to mention it is a $300 almost exhaust setup.[:@]

Thanks guys,

Norman Ross

P.S. Silversurfer you were almost dead on according to what DA told me.

Norman, the tuned KS1060 setup from DA is $200. I have it and it works great with a 23-8 mejzlik. I run a 22-8 on my other DA50 with pitts muffler, I like that prop very very much. I have not tried the 22-10 mejzlik but it might be a bit too much for break in, IMO. DA does recommended it though. I can't imaging running the zinger on this engine, it's just not a real good prop for the application, IMO. Get some gas through this puppy and have fun!

Joe

22 x 10 Mejzlik is not too big. I broke my DA-50 in on it and it turned 7300 rpm right out of the box. No problems with over heating at all.

Futurase, I have about $200 worth of props (MSC, NX, Bambula, Menz, ProZinger, Zinger, Top Flight) I tried on my DA50 in sizes from 22x8 to 24x8 and everything in between from 8-12 pitch. And I have always gone back to the Menz 24x8. It is simply the best 3D prop out there, for me - AFTER you get the engine broken in. I read all the stuff about how this prop or that one was better than the Menz. Just save yourself a lot of grief and break it in on the Menz 22x8 then go to the 24. Now if money is no object then you can start to look at the CF stuff I guess, but thats another issue I haven't tried yet.