Trying to break it in without breaking it...
 

Hello everyone, I am trying to break in the motor on my Nitro 3 RS4 RTR Drift, I know most of you know, but it has the Nitro Star3.0 motor. When I first got it running, and let it sit through the first tank idling off the ground, the idle was really high, and the wheels were spinning, if I set it on the ground, it would go off on it's own, but if I hit the breaks, it would stall.

So I started reading through the posts here, and looking for more 411 on the internet, and what I found out was that I was supposed to adjust the linkage to the carb, (I thought this was already done since it is RTR). So I adjusted it, to what it says it should be, but when I started the car again, it idled so high, I was sure the motor was going to be blow, and I would have to get a a new one, and start all over.

Should I have the throttle trim set to midway? That's also what I found out should be done, but if I tried to trim it back down, nothing happens. Can anyone tell me how many turns out from full closed I should have the idle set at? Mind you, I'm still needing to break this in. I think I also may have a leak, because fuel keeps dripping out where what I assume (new to RC, only know about full sized motors) is the exhaust manifold, I'm going to try a quick fix with some high temp silicon sealant (just temporary), and see if that works.

Anyone have the same car? Can anyone maybe post some pictures of their linkage? Maybe I am way off? I should also add, that I can't go to my LHS, as I live in Okinawa, and they only speak Japanese. I also don't know anyone who has a nitro car, they all have electrics, so that kills that. Any help will be greatly appreciated. Thanks for everyones time.

Kevin

RE: Trying to break it in without breaking it...
 

Your throttle trim should be near zero. You should only adjust idle by the idle screw. You shuld do all your linkage and remote adjustments when the car is off. Take teh air filter off and look inside the carb. When remote is on and car is on (not running) you can adjust everything. At idle the carb should only have a gap of about 1-2mm. Then press full throttle the carb should open all the way but not past full open because it will stress the servo and carb linkage. All you initial adjustments prior to starting should be done with carb and carb linkage with remote set at zero that way teh carb is closed when you start it. You can use the remote to adjust the carb to open slightly to aid in starting and warming up but should be placed back to zero once its warmed up. You also need to set your steering endpoints and braking.

RE: Trying to break it in without breaking it...
 

So if the throttle trim is not at zero, but the carb is at about 1mm then I need to readjust right? How many turns out from closed should the idle screw be at? Should I just close the idle all the way, and go from there?

RE: Trying to break it in without breaking it...
 

Take teh linkage off the carb. Now manually close the carb with your finger. Take a screw driver and either close or open the carb to about 1.5mm. Now turn on your remote and truck (not running) Hook up your linkage. Put remote to zero. Carb should be closed at this point. If not then adjust your linkage to where carb is closed at idle. Now you need to set your max end point. Press the throttle all the way slowly and watch inside the carb to see how far it opens. The carb should only open up till you cant see it move anymore. If you feel it opens further you need to adjust the remote where it says max. Not sure if that made sense. You just need to get familiar with all your adjustments on the remote and figure out what everything controlls. It takes some time but once you figure out how everything works it will make perfect sense.

RE: Trying to break it in without breaking it...
 

OK, I'll give that a shot, that's what I was toying with last night, but I'm almost certain I did it wrong. Still wondering about the idle screw though... I think at this point that might be the biggest problem.

RE: Trying to break it in without breaking it...
 

To add to TwoManyToys very good help, you can adjust your idle screw this way:

Put on the brakes and make sure carb is still open that 1 or 1.5mm.

1/ If not, adjsut idle screw until it is.

2/ Idle screw should limit maximum closure of the carb, even when the brakes are on.

Also....very important I think:

As stated above, throttle trim can be increased to start a cold engine, then moved back to center once engine warms up a bit.

RE: Trying to break it in without breaking it...
 

So does the throttle trim sit at center or zero? I was always under the impression that throttle trim should be as close to zero as possible, and only recently read otherwise[&:]... I may have some hands on help, turns out a friend of mine used to have a Nitro RC plane.:D

RE: Trying to break it in without breaking it...
 

Planes are a whole different ball game. I set mine as close to zero as I can. I think most do the same thing. No reason to set it at half way because once you go below half way its useless.

RE: Trying to break it in without breaking it...
 

OK, been a few days since I posted on this subject. I replaced the exauhst manifold gasket, thought that all my high idling issues would disappear, but not the case. The motor still idles high (I'd say as if I were holdong the throttle at 1/4), the wheels still spin, about half of my fuel gets spit out the exauhst, and adjusting the idle screw does nothing. I have the throttle trim at zero, and at idle the carb is as close as I can estimate to 1mm. When full brake is applied, the carb doesn't close, so it' doesn't stall anymore. The only way that I have found that the idle will go down is if I mess with the low and high speed needles, but eventually it gets to the point where it stalls. I am at a loss. Could it be something else? I thought for sure it would have been the leak that I had in the exauhst from that bad gasket. Please help a noob out. Thanks.

Kevin

RE: Trying to break it in without breaking it...
 

What are the chances that the Clutch shoes are melted? I've never even really run this thing, most of the run time has beein at the high idle, trying to figure out why it goes off on it's own if I don't hold the break.

RE: Trying to break it in without breaking it...
 

when its idling, and it rolls, is it just starting to roll, or is it off and away? If it is just rolling slightly, then you need to adjust the break so that it holds it still.


Look up the manual for your engine. Look in it and it will tell you how many turns for break in. Idle screw should be set so that the engine just runs. If it still needs to be broken in, it may need to idle slightly higher to finshing breaking in.

Adjust the carb so that it runs real rich without stalling. You should be able to have full range of throttle with out it stalling. Once you have that set and its running, now set your idle to the lowest you can go without stalling.

you want the throttle linkage adjust so that when the trim is set in the center, that the throttle is closed all the way, (making sure the idle is set as low as you can with out stalling) and that the break is just about touching.

Some people will say to adjust idle screws, high and low needles when its off, I do it when its running. do the linkage when its not running. For the idle, I would leave the radio off and use my thumb and hold the throttle closed, start the engine, then with a screw driver lower it till it stalls. Then I would put it up a bit, then start it and if it runs with out stalling your good.

now start it with the radio on. If you have adjusted the linkage, use your trim if needed to make sure the throttle is closed normally.

break in normally...

RE: Trying to break it in without breaking it...
 

If I set it down, it's off and away, not just rolling. I am confused as to what you mean with the throttle trim. When I have it set to Zero (or all the way counter clockwise) it is open just the 1mm (as best I can measure), and when I move the throttle trim to full open (fully clockwise) it opens the carb about 3/4. What you were saying about adjusting the idle screw... I can back it out all the way, and it wouldn't stall. :(

RE: Trying to break it in without breaking it...
 

Now what if when its running you put ont eh brake and turn out the idle screw at the same time. The carb should close more. Dude if I were close I would help you out but its hard to help someone online because we cant really see what is going on an exactly what your adjustments are.

RE: Trying to break it in without breaking it...
 

[sm=lol.gif] Yeah there's quite a distance between Pennsylvania and Okinawa. I'll try the brake and adjusting the idle screw. I still need to keep the HSN, and the LSN flush right? And if adjusting the idle with the brake applied doesn't work, does that mean for sure that the clutch shoes are done?

RE: Trying to break it in without breaking it...
 

You should not have the HSN and LSN flush definitely not.

RE: Trying to break it in without breaking it...
 

That's how they came factory, and that is what the instructions say they should be at for break in.

RE: Trying to break it in without breaking it...
 

This is something else I have come upon during my trials with this car, when I turn the reciever on (after the transmiter is on) the steering servo clicks, and shutters the wheels back and forth. when I tried to center the wheels, it makes a very quite buzzing noise. It is very slow to turn thee wheels left or right. At first I thought batteries were bad, but I changed them, and same thing. Is the servo binding? If so what do I do about it? I almost completely disassembled the car to make sure everything was tight, and feel that I may have fixed the idle issue. I have to wait until later today to run it, and find out.

RE: Trying to break it in without breaking it...
 

Still having the high Idle problem, and the car still wants to get away from me when the brakes are not applied. I keep reading that all adjustments to the needles and screws need to be done when the motor is at operating temperature. I checked my temperature today while it was running, and it never got past 120 F. Any thoughts? Hot and Humid equals lean right? Maybe I'm too rich? That wouldn't make the idle high though right?

RE: Trying to break it in without breaking it...
 

Slow turning might simply be because you are using 4.8v alkaline batteries. I upgraded to a 6v nimh hump pack and the difference is so clear. Turning is now quick. How big is the gap in the carb when at idle? take off the air filter (not when the car is running) and find out.

Lean it out if you can't get it past 120.

RE: Trying to break it in without breaking it...
 

The opening on the carb at Idle is to as clost as I can guestimate about 1mm ( that was looking at the calipers, and trying to get it as close as visually possible). In reguards to the slow turning, I'm almost certain that the servo is bad, today it clicked louder than ever, and it got really hot.

RE: Trying to break it in without breaking it...
 

Sorry to hear you have had so many problems with your RS4. Is this your first nitro? Cause even if its all out of wack, you should be able to adjust everything. Do you have some previous experience with nitro? I just baught a RS4 Drift as well and I can tell you its been great. You might have a bad engine, and if thats the case HPI would probably replace it.

Do you have any pictures?

RE: Trying to break it in without breaking it...
 

This is my first RC car, so I know almost nothing (except what I have learned from FAQ's, and the search button) about nitro RC. I have been trying to adjust things, but I can't set it down with out it running off on me. That and my steering servo is not working at all (haven't even driven it). What would you like pictures of? I just got another SLR, so I'm eager to put it to use. Linkage? Car in general? Carb? Hell I can make a vid if anyone thinks it will help them help me to help my car. :D

RE: Trying to break it in without breaking it...
 

Just a Tip id post: On a new engine let it idle for a whole tank of fuel before you start tunning the needles and such.
I was at the track one day and someone did that. And yes pics would help.

RE: Trying to break it in without breaking it...
 

It's idled for about 6 tanks of fuel now. I shall take lots of pictures and a video then.

RE: Trying to break it in without breaking it...
 

Where in PA are you? I am in NJ, if you are close, I'd consider taking a look if you wanted to meet half way.

Its weird, it shouldn't be that hard to tune. Even it the screws are all the way in or out. It should be easy to get it tuned in a couple of minutes.

What % nitro you using? What kind of clutch does it have?

I had a problem with some ones RC10gt that I helped build. Well, I ended up building it. We just set the brake to engage just enough so that the car coasted to a stop when the throttle was let go. After a short while of running, it started to work its self out. the idle went down on its own a bit, and with a little bit of fine tuning, it idled perfectly.

do you have a slide carb or a rotary? the lsn seems like your problem. Turn it in until the engine won't stay running, then back it out in 1/16ths till it idles with a little smoke, not a lot. If your getting too lean on the lsn then it may idle hight.

the other thing you are going to want to look at it, make sure the carb is tight. that is is not loose and not letting any air in anywhere. make sure there are no missing screws or anything letting air in.