Nitro rustler keeps trying to move on idle

[yfzracer450]

Hello. I bought a brand new nitro rustler with the 2.5 engine about 2 month's back. I've been having this same annoying issue since day one. On idle it keeps either moving or I can watch the spur gear like chattering and the wheels like rocking back and forth. I have the tune set pretty good at least I feel like it is. I will do wheelies and it sounds good at wot and has a nice steady smoke stream coming from exhaust. I already replaced the clutch shoes and bearings yesterday but I still notice it doing it. I set the idle to like .7mm which is what traxxas recommended but still same thing. It's not as bad now but it acts like it wants to move. Any suggestions please?

 

[fstnd]

My nitro's do the same (moving the spur back and forth). As long as the wheels don't turn while idling on the ground it's fine

 

[yfzracer450]

My nitro's do the same (moving the spur back and forth). As long as the wheels don't turn while idling on the ground it's fine

Ok thanks I watch so many YouTube videos on tuning and everything else and I see all these ppl where their cars just sit and don't move back and forward but they are usually not traxxas cars. I am really new to this and I wanted to do everything on my own as I enjoy it. That's why I got nitro instead of electric. I didn't wanna just plug and play but I have been messing with the tune so much trying to get rid of that problem to now end but If it's going to do it no matter what then I'll leave it alone lol

 

[fstnd]

Glad you worked out the tuning My poor F4.6 went through lots of tanks of abuse before I figured it out.

 

[yfzracer450]

Glad you worked out the tuning My poor F4.6 went through lots of tanks of abuse before I figured it out.

Believe I've gone through a good amount of tanks trying to get it figured out. Especially with the issue of it trying to move. I kept tuning it trying get rid of it. But I still had fun doing it and that's all that matters

 

[yfzracer450]

So I took it out yesterday and ran like 3 tanks through no problem and it ran great! You said as long as the wheels arnt actually moving then the spur gear rocking back and forward is ok correct? So it would sit still it would rock and the wheels would move back and forth to but barely but it would sit still on the road and not move at all. I should be good right? Sorry if that seems like a dumb question

 

[fstnd]

I meant the amount of play that every car has. For example, if you turn the spur gear right, it doesn't immediately turn the wheels. On average for my RC's, when turning my spur gears from left to right, it takes the spur gear about a quarter turn before it actually engages the wheels and that's what I mean: the clutch engages enough to "dance" or "shake" the spur gear (going back and forth), but it stops once the "maximum level of play" is reached and the power would actually be put into the ground. Sorry for not using "professional terms", I'm bad with names

(This is the way I see it and the way it sounds the most logical for me)

So it would sit still it would rock and the wheels would move back and forth to but barely but it would sit still on the road and not move at all.

I do hope you're making this a theory and that it's not your car which is actually moving like this

 

[yfzracer450]

I guess I'm a little confused while it'd idling my car sits kinda still now on idle without moving forward. Before it would start actually moving without me pulling the throttle. I adjusted the throttle because out of the box the servo was pulling on it so I got a double idle. One idle at idle and then another on the brake. I took care of that but even after tuning it it wanted to still move forward when I would have it on the road so I kept tuning it trying to get rid of it but never able to. I put new clutch shoes in and I noticed the factory ones looked football shaped and not round. That helped but now it still rocks bell or clutch rocks back and forward so therefore it rocks the spur back and forward. If I pick up the back up the back end the wheels will start to turn but not fast like it did. But sitting still on the road it will like slightly engage the clutch enough to make the wheels I guess rock back and forward but it will actually sit still and not move. Is that normal? Sorry I'm just trying to make sure my car last as long as possible. I love playing with it and I wanna do everything on my own. Sometimes I over think somethings that may just be a simple thing that's a normal thing

 

[fstnd]

I guess we're both confused now definetely I did not want to come over as rude

I'm just trying to make sure my car last as long as possible.

For sure I know that feeling, but here I believe that as long as you're comfortable with it and don't have to smash the brakes everytime to stop it, it really should be fine. What exact clutch did you buy tho? I've had some experience myself with these from AliExpress:

even if they're new, the spring is just factory weak. When using these, I even had to hold the brakes a bit to stop it.

if you can, please share a video

 

[yfzracer450]

I just bought the factory traxxas ones I showed them the picture from traxxas website and that's what I got. It's plastic ones like in the picture. But no, now I don't have to hold the break to keep it still. The only time it does start to idle up and will actually move without me hitting the throttle is when it's about to run out of fuel which is normal. But I guess the right word I should of used is the tires twitch. So as the car is idling the clutch is like engaging ever so slightly and making the wheels twitch and the spur gear to actually rotate back and forth but only like 2 or 3 teeth it moves forward then back. Kinda like I'm pushing the car forward a hair then pulling it back a hair but now it actually doesn't move. If I lower the idle same thing. I had the idle so low before as I was trying to learn that it would actually stall after 1/2 a tank all the time. Once I I learned that and set the idle properly I don't have that problem. Like I said it will do wheelies and scream at wot but the spur gear still twitches. It won't just sit stationary and not move at all until I hit the throttle. But traxxas told me that's normal but I was just wondering if anyone else ever had the same issue and I'm just being paranoid

 

[yfzracer450]

I guess we're both confused now definetely I did not want to come over as rude

For sure I know that feeling, but here I believe that as long as you're comfortable with it and don't have to smash the brakes everytime to stop it, it really should be fine. What exact clutch did you buy tho? I've had some experience myself with these from AliExpress:View attachment 171857even if they're new, the spring is just factory weak. When using these, I even had to hold the brakes a bit to stop it.

if you can, please share a video

I'll have to add a video when I get home Sunday or Monday. I work out of town on the weekends so I'm unable to play with my car

 

[gandalfnz]

A video of the car running would be great.
Fact is, Traxxas nitros do not idle well at all, and idle high, which sounds like your issue. Their carb design is terrible.
If you would consider buying OS 11k carb and replacing that poopy plastic Traxxas one, it will make a big difference in the way car runs and keeping a tune.

 

[yfzracer450]

A video of the car running would be great.
Fact is, Traxxas nitros do not idle well at all, and idle high, which sounds like your issue. Their carb design is terrible.
If you would consider buying OS 11k carb and replacing that poopy plastic Traxxas one, it will make a big difference in the way car runs and keeping a tune.

Thanks for the advice. I'll have to look that up later and see how much it cost. As for a video I'll have to wait till Sunday evening or Monday when I get home from work. I am very new to this so this is all a learning process for me. I had a tmaxx as a kid but when I say I did nothing to it I mean nothing. I never tuned it or anything and I don't think I made it through a gallon of fuel before it got destroyed and burned itself up basically. The throttle linkage goes over the spur gear and apparently it was close enough for the gear to grab the linkage and wot throttle it. By the time I got to it the clutch area was glowing red and after that it never ran the same or at all and it just sat in the garage till I sold it. Rip tmaxx

 

[gandalfnz]

Traxxas engines are good, carb is not.
The trick when tuning the traxxas engine is to adjust the idle with LSN after idle screw has been backed out to its max.
There is no other way.

 

[yfzracer450]

Traxxas engines are good, carb is not.
The trick when tuning the traxxas engine is to adjust the idle with LSN after idle screw has been backed out to its max.
There is no other way.

This may seem like a dumb question and I'm sorry but By backed out do you mean closing the idle gap so making it smaller? Because I was doing that but then I ran into the problem where I guess I had the idle so small that even though it would start right away and run good it would stall after about 1/2 tank all the time. But once I reset everything and set the idle to like the thickness of a credit card which I read was like .7mm then that problem went away but it still trying to move on idle was still there. The more videos I watched on YouTube the more I learned that I basically have to adjust the lsn with the idle. I was never doing that. Now I set the idle then I started from factory flush on lsn and turned it out counter-clockwise then went from there still same thing. Even though it runs like a champ. I'll figure out how to load a video tomorrow when I get home. I attached a picture of the old clutch shoes as well. They are on the right and new on left. The old ones look football shaped and they were the factory ones with like maybe a 1g of use on them

 

[fstnd]

but it still trying to move on idle was still there.

One day the clutch will just wear out and engage later

I've got another AliExpress experience BTW, with these 3 shoe clutches:

They are a PAIN to assemble but very stiff. As I ruined one of the springs, I've got 2 left and from the 3 shoes I'm using only 2 on my savage. It works really great and engages later than the standard 2 shoe clutch:

But I understand that a force .32 will idle lower than a trx 3.3

Alright but now I'm not planning to EVER disassemble the clutch as it's so hard to assemble

 

[gandalfnz]

This may seem like a dumb question and I'm sorry but By backed out do you mean closing the idle gap so making it smaller? Because I was doing that but then I ran into the problem where I guess I had the idle so small that even though it would start right away and run good it would stall after about 1/2 tank all the time. But once I reset everything and set the idle to like the thickness of a credit card which I read was like .7mm then that problem went away but it still trying to move on idle was still there. The more videos I watched on YouTube the more I learned that I basically have to adjust the lsn with the idle. I was never doing that. Now I set the idle then I started from factory flush on lsn and turned it out counter-clockwise then went from there still same thing. Even though it runs like a champ. I'll figure out how to load a video tomorrow when I get home. I attached a picture of the old clutch shoes as well. They are on the right and new on left. The old ones look football shaped and they were the factory ones with like maybe a 1g of use on them

If it works fine from full to half tank, then its not the idle. You could be lean on one of the needles.
Sounds you got the hang of tuning already, keep at it until it runs right.
Difficulties with tuning, get an OS 11k.

 

[yfzracer450]

How do I upload a video to here? I tried to attach files but it said something about it not being right or something and wouldn't let me

 

[fstnd]

Yeah really you can't. A quick way is to sign up for mediafire (free) and share a link so we have to download the video. But last time I did this on the large scale forum they were frightened they'd install a virus
You can also post and send link from youtube

 

[yfzracer450]

Oh ok thanks ill look at later when I get off work. Illl try and make a video when i get home this evening if not illl do it tomorrow. I want someone that knows nitro rc to actually see what the hell I'm talking about