techsarge

My Feedback: (1)

Went to flying field today and for some reason the carb barrel binds up when it's fully closed. Tried everything I could think of and then when I got home I looked at it again. I decided to close the barrel down so there was no opening and then closed down the barrel spring screw. Now the barrel doesn't move as far in the the closing process and it seems to operate pretty smoothly. Anyone make any sense out of the problem I had and does it seem that what I did with the screw adjustment makes sense? It seems like there is a point where the barrel closes excessively and binds. Any comments? Oh, the servo and the throw seemed to be fine...Thanks...

Ed

Not24

My Feedback: (1)

The screw that controls the closing travel, the one with the spring on it, is most likely not to blame here. My guess is the other screw that acts as a pin and rides in the slot of the carb barrel. Your slot in the barrel may not be machined deep enough or wide enough and at full closed position it is binding. Try first loosening this screw and work the throttle by hand. If that doesn't do it, remove this screw and try it. With this screw removed, the spring tension will push the barrel out of the carb body. If it's not binding with that screw, look for burrs in the carb barrel and the carb body bores.

techsarge

My Feedback: (1)

Hi...

Thanks for the tip. I did try that at the flying field. I backed it out several turns and it still hung up. What made me suspect the barrel stop screw what that it was backed out quite a bit. I could manually rotate the barrel full closed and it felt like it hung up on a bump. At that point I had to manually rotate it to open it up. When I adjusted the barrel stop screw by turning it in, it adjusted the location where the barrel stopped which was apparently short of the position where it had hung up and there was no binding. Is it possible that if the barrel closes past a certain point, it will bind because the barrel goes beyond where it should it hangs up maybe because of the position of the bolt that you suspect might be causing he problem? I'm going to try to run the engine on Monday to see what effect the position of the barrel stop screw has. Thanks again...

Ed

Not24

My Feedback: (1)

My 2300 won't shut off with the throttle. I usually touch the prop with my shoe to get it stopped. This happened on both carbs. Getting the carb barrel to close farther made no difference. Will yours shut down with the throttle? Mine just chugs along at 1400 rpm or so. It will eventually quit if you give it time.

Cyclic Hardover

My Feedback: (3)

I usually take that screw out and smooth it down a bit so it does not bind. That has happened to all my st engines. Now I just routinely do it before I maiden it. I have had it stick full throttle and had to fly it dry and deadstick in.

techsarge

My Feedback: (1)

I had the same problem at the end of last year with it not wanting to shut down. THe barrel appeared to be closed but the engine contined chugging along. I pinced the fuel line to shut it down. Read somewhere that the idle might be set rich and this prevents it from shutting down. Leaned it out yesterday and it appeared to shut down ok.

Worked on it this morning and did a couple of things: I changed the EPA to prevent the barrel from closing too much. Thought that resolved it but it didn't. I took Cyclic Hardover's advice and removed the barrel. I felt the bottom of the screw and I felt a slight burr. I lightly filed the screw bottom and then looked in the groove where the screw sits and it seemed a little rough. But I assembled it and this time it appeared to take care of the binding. Thanks for the help...

Ed

Cyclic Hardover

My Feedback: (3)

Sometimes it gets real stupid. I can sit their and run that throttle on the ground for an hour and nothing. Put it up in the air for 5 minutes and it sticks. Thats why i started dealing with it before I fly any new Super Tiger.

techsarge

My Feedback: (1)

Thanks for that tip. It appears to be ok now but I didn't run the engine. I tried to go past the point where the barrel is fully closed and with the barrel stop screw(spring-loaded) set and the EPA ajustment on the radio set, there doesn't appear to be any binding. The groove that the screw you mentioned rides in appears to be a little rough at one end (the end where the barrel is fully closed but I don't know what I could use to clean that up. I suspect that that rough area at the end of that groove and the burr on the screw were causing the problem. Tell me if this makes sense: If I use my radio EPA to prevent the servo from moving the barrel to the point where the screw contacts the rough spot in the groove, that should resolve the problem. In addition, by setting the barrel stop screw to prevent the barrel from rotating to the rough spot in the groove that also should make the problem go away. Am I making sense or am I more confused than before? Appreciate your time...

I'm using a braided cable and wonder if I should go to a solid pushrod instead? Can't imagine why it would fine on the ground and bind up in the air? Maybe metal expanding from the heat? Probably more like magic...

Ed