Hey guys i am working on my first nitro that i bought used it had an older 72MHZ RX so i replaced it with a Spektrum AR8000. I hooked everything up and it seems to be working fine except for the throttle cable/ pushrod the servo moves a little but the cable/pushrod flexes instead of just pushing and pulling does it need to be moved to another hole or just adjusted where it is screwed down on the pushrod?

Remove the throttle servo control arm.

Then try moving the throttle on the TX.

Does the servo respond correctly? I bet it will.

Now try moving the pushrod in and out.

I'll bet the throttle barrel is seized because the engine has been sitting for a while.

See if you can work it loose with some WD-40.

If the throttle valve is stuck it is probably because of congealed castor oil residue. The easiest way to fix that is heat. If you have a heat gun, play it on the throttle/carb area and get it very hotso hot you can not hold it with your bare hand. Work the throttle arm back and forth and it should quickly free up. Once free, put some fresh fuel or after run oil in it and work it a bit. WD40 is not a recommended solution. WD40 is a water dispersant, not a lubricant, and can have adverse effects if there is rust involved as it will loosen the rust and turn it into a nice scouring compound to wear out the innards on you engine.

Since you are using Spektrum (cant speak for other radio mfgrs)....IF you have to reverse your throttle AFTER you have bound it. You need to REBIND after reversing.<div></div><div>If you dont...your throttle failsafe will be WOT (Wide Open Throttle).</div><div></div><div>This is often overlooked...even I have found a couple of models in my collection that I forgot to do this process. Luckily I never have lost signal to see the result.

I know my reply does nothing to help your original question. But since I assume you are new, I figured it wouldnt hurt to put this little piece of valuable info here for you to learn from. If you already know this...sorry for posting and taking up room in the thread.</div>

Never, Never us WD 40 as a lubricant because as mentioned above it is not. Good advice given by Rodney.
I had several engines that sat for 3 years before getting back and I used heat. I took the carb off and removed the o-ring to prevent that from being damaged and then applied heat. Worked great and the engine started up first try. Good luck.

Sorry that is quite incorrect.

WD-40 - IS - a lubricant... It is a VERY effective one too... It is oil based.

It may loosen rust, and it can be used to flush any rust loose followed by a liberal rinse with either more WD-40 or glow fuel.

If WD-40 loosens rust, so will glow fuel with the heat of operation under normal circumstances... and that being the case a good cleaning is in order anyway.

I've used WD-40 in several dozen engines to get siezed engines back into operation, as part of a complete cleaning.

-

Better still apply Dawn Power Dissolver internally, flush with hot water, follow that with WD-40.

Clean the carb, re-assemble and fly.

I've salvaged dozens of absolutely black and siezed engines this way.



Myth: WD-40 Multi-Use Product is not really a lubricant.

Fact: While the “W-D� in WD-40 stands for Water Displacement, WD-40 Multi-Use Product is a unique, special blend of lubricants. The product’s formulation also contains anti-corrosion agents and ingredients for penetration, water displacement and soil removal.

From the "horse's mouth".

http://wd40.com/about-us/myths-legends-fun-facts/

Once you get the throttle working (I have used lots of WD-40 to loosen up a stuck throttle as I have some 150 engines +/- thrown in drawers and many get frozen up until I need/want one) then do yourself a favor and change out the throttle pushrod to a straight solid wire one, which will accept slight curves if inside a plastic tube, even a drinking-straw will usually work OK. Cable throttle push-rods are just an item to cause problems, especially when throttle trims are digital. IMO any digital trim is pure horse-poop, but that is 50 years of using analog which works exactly the way trim is supposed to work. OOPs so sorry, just went off-topic. How bad I am ????

It's a small point but I am sorry but you are NOT correct. WD 40 is not a lubricant, it is a combination of a lubricant, penetrant and a water displacement.

"A lubricant is a substance introduced to reduce friction between moving surfaces."

"Penetrating oil, also known as penetrating fluid, is very low-viscosity oil. It can be used to free rusted mechanical parts (such as nuts and bolts) so that they can be removed, because it can penetrate into the narrow space between the threads of two parts. It can also be used as a general-purpose lubricant, a cleaner, or a corrosion stopper. Using penetrating fluids as general-purpose lubricants is not advisable, because such oils are relatively volatile. As a result, much of the penetrating oil will evaporate in a short amount of time, leaving little residual lubricant.."
Now do we all use it as a lubricant, sure including myself, but when it comes to airplanes especially real aircraft WD 40 does not fall into the lubricant category and is not allowed to be used as a lubricant.
As far as the WD 40 web sight, really, it's a household product what do you really think they are going to say?
Enough said.

What ever works, I have used WD-40, Acetone, break cleaner and mixes of all of it. Most the time I just use the heat gun then just start the engine. The Castor oil in the fuel will lube the carb very well. No reason to remove the carb or O-ring with a heat gun, the engine will get hotter just from running.
Little known use for WD-40, it removes scale and hard water build up from the shower stall, just spray it on, 10 minutes later use a Teflon sponge to remove the build up. Only stinks for about a week but the glass is spotless. It's also a great starting fluid. Good stuff, even removes those nasty price tags you can't peel off with a knife and bugs from the front bumper of your car.

Oh PLEASE.... What's next the definition of "is"?


No Bill, it is a lubricant.

"A lubricant is a substance introduced to reduce friction between moving surfaces."

Which by definition it does.

I've used WD40 and followed up with Marvel Mystery oil after it broke loose.
I wonder how sewing machine oil would work?

Saying WD-40 is not a lubricant is absurd. It may not be ideal for all lube jobs, like high viscosity oilwould be. But for sure it is a lubricant. Even after mostof it evaporates, isnt there still a little oily reside behind? That says itall. I have freed up dozens of frozen engines over the past 30+ years and havenever had any issues. If you want to soak your engines or Carbs in something for a while to loosen themup, I have usedeverything from deisel fuel to olive oil. A good cleaning/wipedown afterwards and your good to go. Rotten Out

Rather than argue about what is, what may be and what is not a lubricant, let's take a step back (since we don't actually know if the carb is the issue in the first place)
and offer some usable advice.
to p3arljam, I'd suggest removing the pushrod at the carb and try moving the throttle servo, and try moving the carb barrel by hand.
that should help isolate where any binding is happening.
IF the problem is indeed that the carb is frozen/binding (but the pushrod moves freely) regular old glow fuel (poured directly into the carb and the barrel) should free it up.
try that and please post back.

WD40 stands for W ater D isplacement after 39 trials. They made it work on the 40th attempt.

Wphew.. How quickly the point of the original post goes awry.

WD40, Marvel Mystery Oil, fuel, whatever works.

As for me, I soaked an old engine, a somewhat vintage OS 61 SF that I bought at an estate sale, in a coffee can that I filled with ordinary glow fuel, high enough to cover the engine, and let it sit for a week. After that, I cleaned everything out, mounted it, and started it up. It ran just fine. Originally, the throttle would not move hardly at all. After the soaking, it moved like a new engine. Do what ever you need to do to free the carb using any method. I liked my method because it exposes the engine to exactly what makes it run and it both dissolved the old crud and lubricated, heck it contains 20% oil blend, so why not.

But let me offer this one point. Hoss said it, but there may need more said here. I would disconnect the linkage and see how the throttle works. If it's gummed up, well, read the above. If it is NOT, then there is something going on with the servo or linkage or both.

I have offered this method to several people in the past, but here it is again.

1. Make sure your throttle channel does not have any expo, end points, or anything like that - meaning that it has full movement end to end, then, using your transmitter with all trim removed, electrically center the servo. This means put your throttle stick on the transmitter in the center, as close as you can get it visually.
2. Mount the servo in the proper servo slot in your fuselage.
3. Put a servo arm on making sure you select one of the arms that will be perpendicular to the side of the servo that is in parallel with the throttle on the engine. The splines in the servo shaft and inside the servo will pemit rotating it to find the one position that provides a good perpendicular mounting.
4. Center the throttle on the engine.
5. Connect the linkage shaft being careful not to move either the servo arm nor the throttle. I would suggest a Z bend on the servo and a plastic clevis on the throttle. Twist the clevis so that you have plenty of adjustment room, both in and out, in the threads This will prevent any metal-on-metal friction that can often cause electrical interference due to vibration. Using the clevis, adjust it so that both the throttle and the servo arm are both centered. One point here. I would choose a center hole in both the throttle arm and the servo arm. This will give you room for mechanical adjustments that will surely happen. Re-check centering. If it all looks good, then continue.
6. With both ends of the linkage connected, SLOWLY move the throttle stick to full open then to full closed. No doubt, there will be either to much movement or to little. The goal here is to have the throttle fully open when the stick just reaches full travel. No more no less. Any less and, well, you won't get full throttle. Any more and you will bind up the servo and either break a tooth in the servo spline, drain your battery, or both. A small point here. I use a gadget called Voltwatch2. It can be plugged either into an empty receiver slot or, using a Y cable, into any of the used slots. This will give you an outstanding indication if you are having throttle binds.
7. Adjust the linkage at the clevis to the point where full open has the throttle fully open - again with no binds, but with the idle end, adjust your trim so that it is fully closed then pull the throttle to fully closed position. Re-check the fully open again because the trim will affect both ends of movement.
8. You can move the throttle linkage to any pair of holes in the arms as necessary, but watch out. You can lose resolution if you are not careful. Spend some time on this.
9. Repeat as necessary until you are satisfied with the way the throttle works.

I admit that this could be a long process, but if done right, you will have a smooth operating throttle from idle to full open with room on the idle side to operate a cut-off button or switch, on your transmitter and you will have absolutely no binds in the linkage.

Good luck.

CGr.

Water will absolutely reduce friction between two moving surfaces. Therefore, it is a lubricant.

There was a question in one of the service wide exams I took when I was in active duty. It was a promotion exam to go from E6 to E7. The question was:

Which one of the following is considered "the universal solvent"?

It was multiple choice. I don't recall all the answers provided, but the correct answer was water. So, water could serve as both a lubricant and a solvent, I guess.

Ok.. enough straying from the subject of the thread. Let's get back to the original subject and help this guy out.

CGr.

Yup water is a lubricant too...

Going by the circular logic used before, oil would not be a lubricant because it displaces water!

-

Anyway back to the OP...

I'll bet his throttle barrel is frozen and needs to be loosened up.

It would be best for him to loosen it, WD-40 works great... then remove the carb and clean it out as it may also have gunk in the needles and nipples.

how about wd-40 contains lubricant.... :-P





As for the original post. if the throttle barrel isn't seized, often times the pushrod just needs to be supported in some form or another to prevent flex. fashioning some sort of bracket/brace out of spare balsa is pretty common and helps to remove the flex in the shaft.

Hi!
How about just heat it with a heatgun!