little help on DA50

[rede2fly]

ok guys ive been running this da 50 for over a year now with no problems at all. have not had to even touch the needles. running top notch. so today i go out to the field and did everything as everyday but when the da fired up it idles perfect but when i went to go to w.o.t. the motor dies. now i figure its a carb problem but not shure. nothing has changed its not lean nor is it rich it ran perfect up to right now. and it wont go to w.o.t. without dieing W.T.F. battery is good servo is good gas tubing is good no air leaks. what do ya think. rebuild carb?? dont have another to replace it with to check.

[rede2fly]

thanks for the help but i found the problem. no no really thanks

[pitts2b]

glad u found the problem! wuz it the carb?

[sweetpea]

bad plug?

[rede2fly]

yea it was in the carb. the screen was full of crap which is really hard to beleive. i run 2 filters in the fuel tank for the main gas, and then another 1 to the carb. go figure. but i just put a ceramic filter in the plane fuel tank which i think was the culprit. the tiny bits off of that caused the problem i beleive. so back to a plane clunk and forget about the upgrades 1st flight and the jug turned pink and quit. 1st dead stick on my DA ever. after disassembling and cleaning the carb out the motor was back to perfect and the jug is turning back to its regular color. xoar 22x8 7200 then backed to 6950 r's. stinking 5.00 ceramic clunk. learned my lesson

[MrAmmo]

I have an issue I hope someone can shed some light on. My DA 50 runs good yet I cannot get the throttle respose linear to stick position. Max RPM is obtained at 60% of the throttle/ servo/ butterfly opening, leaving a dead zone on the stick from 60% to wide opening. I have tried props and even considered adjusting out this dead zone in the transmitter but woulld rather have it smooth throughout the stick movement, 22 X 8, at 7100 rpm. Ideas??

[FLZman]

When you set up your linkage, were you able to keep your ATV/endpoints at 100/100? I always shoot to keep them at 100/100 and mechanically hook up servo and throttle arm so that low stick is fully shut and throttle isnt fully open until the stick on radio is fully open. If you do that, your throttle should be linear.

[DR10044]

	Quote: Originally Posted by rede2fly
	yea it was in the carb.

Glad to hear you figured it out. Where do you have your needles set for both high and low?

[reyn3545]

	Quote: Originally Posted by MrAmmo
	I have an issue I hope someone can shed some light on. My DA 50 runs good yet I cannot get the throttle respose linear to stick position. Max RPM is obtained at 60% of the throttle/ servo/ butterfly opening, leaving a dead zone on the stick from 60% to wide opening. I have tried props and even considered adjusting out this dead zone in the transmitter but woulld rather have it smooth throughout the stick movement, 22 X 8, at 7100 rpm. Ideas??

Its the carb, but its not a problem. Most folks will brag about how their Yak will hover at 1/3 throttle, but they don't realize that at 1/3 throttle, the motor is probably turning at about 2/3 its maximum RPM. There's nothing wrong with your motor.

If you want the throttle response to be more linear, you'll need to set up a throttle curve.. introduce some expo into the throttle setting. Usually about -60% will give you a nice smooth transition from end to end on your transmitter.

First, make sure that the end points are correct, then set your transmitter throttle stick at the midpoint, and using the expo settings on the throttle channel (and a RPM meter on the prop), just add expo until half-stick is about half-speed on the motor. Your curve will be almost flat on the lower end of throttle stick movement, then start to rise sharply as the stick moves more towards the high end.

[Flatlandman]

	Quote: Originally Posted by FLZman
	When you set up your linkage, were you able to keep your ATV/endpoints at 100/100? I always shoot to keep them at 100/100 and mechanically hook up servo and throttle arm so that low stick is fully shut and throttle isnt fully open until the stick on radio is fully open. If you do that, your throttle should be linear.

Almost completly right here except its not 100/100 you shoot for its the minimum try to get it higher and keep it equal on the open and closed perfect would be 150/150 and if your end points stop at any number wether its 200/200 or 125/125 try to get it as close to those numbers as you can. Most times you can get only to ~130 out of 150 but its still better than 100 out of 150 you see.

[rede2fly]

	Quote: Originally Posted by DR10044
	Glad to hear you figured it out. Where do you have your needles set for both high and low?

not shure i didnt count the partial turns after turning them both out 1.1/2 to start then using tach to set final plus using ears. it wasent far from the orignal turn out. also i set my linkage to make shure the butterfly opens as the throttle is advanced, so i dont have that dead zone feeling. i notice it on others peoples but i dont say anything. most people dont like hearing that their set up is incorrect

[FENWAYFLYER]

	Quote: Originally Posted by Flatlandman
	Almost completly right here except its not 100/100 you shoot for its the minimum try to get it higher and keep it equal on the open and closed perfect would be 150/150 and if your end points stop at any number wether its 200/200 or 125/125 try to get it as close to those numbers as you can. Most times you can get only to ~130 out of 150 but its still better than 100 out of 150 you see.

What size servo arm is best to run. I always seem to be messing with my throttle curve and expo but always just give in and fly the damn thing.

[zoomer260]

	Quote: Originally Posted by FENWAYFLYER
	What size servo arm is best to run. I always seem to be messing with my throttle curve and expo but always just give in and fly the damn thing.

No such thing as "best". Depends on your servo and carb. We don't want even throttle arm travel we want even "response" from the engine. Throttle curve and patience is the only way I see it possible. Expo if ya will.

Dang I did not think of that but it would seem that expo would act as a throttle curve ? Since everything I have ever run with a Walbro style carb has full throttle response at about 80% or even less butterfly opening would expo on the throttle channel not serve as a throttle curve to some extent ? My old XP783 does not have throttle curve for planes.

I mean a true lineir throttle cannot be achieved but less throw at the beginning of stick travel would go a little way to help it out ya think?

[Flatlandman]

I use the smallest servo arm i can. If the throttle arm is 1 inch long start at 1 inch and then shorten it if your end points are to low.

My throttle set up goes get max end points equal open and close then if necessary set a throttle curve to make the power linear not rpms. I fly the plane and if the plane has to much power like if you want to hover near center stick then you can adjust the curve to suit this.

[MrAmmo]

Thanx allot for all the input! I do have the servo and butterfly completely linear and at 100%.
But will work the throttle curve issue, expoential. I have flown others that have the same dead zone and too, have not really commented. Faith in the forums!