init4fun

In the gas engines sticky , I read that its a good thing to disconnect the throttle return spring . This seems like a great idea , so as to not have the tension of the spring constantly loading the servo , causing it to draw excess current ... Ok , All well and good . But , the sticky also said to not remove the spring , just to disconnect it . My question being , that if its no longer going to be spring loading the throttle arm , why NOT take it out of there completly , rather than leaving it loose to rattle on the shaft , and possibly cause that "loose metal rubbing together interferance" . It seems to not steady the shaft in any way once unhooked , and is pretty loose and rattling in there .

Anyone got an answer ?

w8ye

My Feedback: (16)

It does steady the shaft. It centers the butterfly inside the throttle bore.

captinjohn

If the spring has a rattle....take it off and strech it a bit and place it back. Take our word on what has been posted. It should stay in there....also no need to unhook it. The only time the spring will have any strong pull is when the throttle is wide open. Most engines th RPM does not increase after 3/4 wide open. A standard good futaba servo is good. Use a long arm on the throttle shaft really helps. Capt,n

goirish

I don't dis-connect the spring, only for the reason if the throttle cable/push-rod ever come loose the spring will return the engine to idle. Just my 2c

repinfl

My Feedback: (40)

This theory and it is just a theory of not taking off the spring is an old wives tale!
If you just look at the carb you can see the butterfly and shaft are secured via "c" clips
and does not depend on the spring to center it. I have always taken off the springs and have
engines 30+ years old and still flying that had no ill effect from taking off the spring. I used
to take them off because of fear of interference from it rattling around but I do not think
that is the case with 2.4. I do not claim to be an engine guru as some here do but that has
been my experience in my 61 years in this hobby/sport!

w8ye

My Feedback: (16)

This is not always the case. There's just a C-clip on the end opposite the throttle arm on some carbs. Some carbs have arms on both sides. There's all different kinds of variations.

3136

Read post 13
http://www.rcuniverse.com/forum/m_10...m.htm#10812981

acerc

December 10, at an event called, Twelve-o clock high, a fellow club member was flying hisplane, just a couple of minutes into his flight the throttle linckage gave way. After flying around for a good fourty minutes he finally landed dead stick. He say's there two thing's he need's to do to his plane. First-hook the spring back up. And second- make a second mean's for killing the engine.

HunkaJunk

I take the springs on my gassers completely off,  none of the carburetors I run need the spring to center the butterfly, there is generally a c clip on one side and a screw and spacer under the throttle lever that centers it.   I can kill the engine from the TX without the use of the throttle switch so a throttle servo failure would not be an issue.

init4fun

Wow , the answers all all very much appreciated !

Now , since it would appear that in some cases the spring does center the butterfly , Yea , i could see the point in not removing it . In the instance of the engine im looking at , an RCGF 15 , the spring once disconnected is really loose , and doesnt appear to put any side pressure on the throttle shaft plate at all , its not even touching it . I had considered trying to anchor the spring elsewhere so as to keep tension on it and keep it from rattling around , but I think I'll go the easier route and just take it out .

Ive only got two gas engines , the RCGF 15 and an SPE 26 . I havnt yet flown either , or even run the SPE , and the RCGF has had a bench run one time only (and yes , it is a "version two" hub)

I'll have to dig the SPE out of storage and check if its spring centers its throttle shaft or not .

I just know from years of flying glow that Ive never seen a spring on any of our engines execpt on the old 3 line control line setups that had the throttle spring loaded wide open , and pulling on the third string would idle it down .... I figure if my Saito 270 (45cc) has no need of a return spring , why should the 15cc gasser need one ?

378

My Feedback: (4)

I'm of the opinion that a throttle return spring will not hurt anything, and that there's no reason to disconnect it.

Truckracer

My Feedback: (19)

Yes, I've seen carbs with (2) C-clips, (1) C-clip, no C-clips, carbs with spacers on one side, two sides, none at all, etc. Just about every combination exists out there. If you leave the spring in place and measure the extra current draw the servo requires it is minimal. There is really no reason to disconnect the spring as it really can't hurt anything being in place and there can be major benefits from having it in place. Seems like a no brainer to me.

I certainly have seen carbs where the spring was removed and the throttle plate dug its way into the side of the carb body making the whole thing worthless. That was all I needed to rethink my once almost mandatory requirement to remove the spring.

captinjohn

Now read this cut and paste below.<hr />Had the user obtained an engine, any gas engine, from a source with knowledge of how they work he would have been better served. From this point forward it's up to those that have that understanding to educate them in the porper operation of a gasser, and the associated components that permit one to funtion in the manner intended. But first they need to know the first basic rules, which I spelled out quite clearly. As to the matter of a voided warranty, perhaps you were also unaware that most of the major manufacturers instantly void their warranty when you remove the carb return spring. The reason for that is because removal eventually destroys carb functionality.

Antique

My Feedback: (4)

CARBURETOR 101[>:]....All Walbro and Tillotson carbs were originally made for something else, not a model airplane...The other users have a trigger to operate the throttle, hence the spring....All Walbros and Tillotsons have a clip or some means to keeo the shaft tight against one end...'
The spring has two functions, to return the throttle to idle and to keep the shaft against the clip or whatever centers is..
When a carb is wide open the disc does not completly fit against both ends of the hole in the carb, the venturi...
The spring's other function is to keep tension on the shaft to hold it against the end and not let it rattle around in the hole..
A carb with no meas to keep the dixc in the center will eventually get worn on one or the other or both ends to a point when the throtte is completely closed there is enough space on the ends to let fuel through and the idle will be too high...
I have been working on these things for at least 25 years and have seen quite a few worn carbs, both on the ends of the disc and both sides of the body wher the disc has been vitrating against it...
Take the spring off if you liike, if you fly long enough you will find that your idle will be too high and the engine can not be cut off with the throttle....PERIOD[>:] If this explanation offends anyone's tender ego, so be it, get over it, it is the truth...
Tillotson carbs have a brass washer and clip...And a spring.
Some Walbros have a clip on both sides, and a spring...
Walbro WTA6 G38 carbs have a spring on one side and a wider clip on the other end screwed into the carb body to keep the shaft centered...
Glow carbs generally have a rotaty barrel with a groove in one end. sometimes straight, sometimes spiral...there is a screw in the carb body with the end turned down to fit into the groove...Some have an internal spring....

av8tor1977

My Feedback: (6)

As usual, I agree with you Ralph.

Snowing up there tonight?

AV8TOR

Antique

My Feedback: (4)

Yes, but not too bad...

raptureboy

I think it would help to know which direction of center we are referring to. The spring keeps the butterfly centered vertically, so that the butterfly does not drop down and rub against the carb body and wear it out. It acts like a spacer where there is only one c-clip retaining the shaft. I agree with the others just leave it on, it places almost 0 load on the servo and acts a backup if something happens to the linkage.

captinjohn

No snow here in Hesperia Mich...nice!!!

On that spring...I bet a person could place a time lasp video with foot notes and there still would be questions from some....lets say ST _ _ _D person. Fill in the blanks!!!!!!!!!!

ec121

My Feedback: (2)

I have had good luck putting a longer arm on the throttle to reduce the force needed to move against the spring. I tap the holes for 3mm or whatever it takes to get threads in the hole then make an arm as long as will fit. Then make the servo arm match the throttle arm's length. Since we are constantly moving the throttle, it really doesn't make much sense to remove the spring. As weak as the spring is, if a servo failed, I doubt if it would have enough force to push against the servo gears to close itself anyway.

captinjohn

Jody who did work at Valley View RC had a good chart (on controll throws) he would post here from time to time. Maybe he will post it again and then we can thank him and wish him Merry Christmas!Capt,n said that!

clivemc

leave the spring in there - all above posts explain why. Virtually no benefit in removing it ever... current draw on the servo doesnt even feature

init4fun

[8D] Well Ive gotta say Thank You !

To have so many who's opinions I trust say to keep the spring , , , Well , then , , keep the spring I will !!!!

Its great to hear the reasoning behind the directive to not remove it , and the reason of centering the butterfly makes perfect sense . I have hooked back up the spring on the RCGF 15 , and never did disconnect it from the SPE 26 , so all is good with the world , , at least as far as carburators goes , in my plane shop .

I will say that there IS some misinformation out there on other sites , , , I'll be darned if I can remember where I read it , but I clearly remember reading people putting forth the (wrong) notion that the spring was just a leftover from the carb's originally intended weedwakker duty , and I can now see that its more than an un needed vestigal remnant of that original intended use .

Its kinda like the heat sheilds over the catalytic converters that people rip off when they rust and begin to rattle ..... " Ahh , ya dont really NEED that" , , , Sure , not till the converter's heat ends up melting something nearby !!!! GM and Ford didnt spend .02 cents per vehicle installing un needed parts , just like RCGF and SPE wouldnt have included the spring unless they felt it was of some value to the continued performance of the engine ......

Thanks Again for the Info [8D]