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Old 05-13-2007, 05:37 PM   #3466
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WOW!

Let me know when your trash pickup is. I'll even take it out for you.


Really, there are a lot of factors about these servos going out. The other prob is an easy to open carb setup. Some carbs, if they are out of line just a little, will not open smoothly.

If you have an RTR the problem is most likely the carb. I have cleaned out every one we have sold. lubed up the slide real good, cut the throttle return spring, put a button head screw on the pull arm rather than the set screw to get the pull spring straighter and then checked alignment to majke sure it is right.
Only then did the normal stuff come into play like EPAs and grommets on the servo.
It is a good idea to put a small fuel tubing on the pull side of your throttle linkage. Let the throttle servo have this extra little bit of padding in case the chassis twist while you are WOT. It will not allow your throttle servo to strain.

Hope this helps.
TEX

Do we need some better pics?
The oring under the radio tray?? Come on... Losi is better than that!
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Old 05-13-2007, 05:58 PM   #3467
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Quote:
Originally Posted by Laysander
is there anyone out there that still using the original spektrum z270 on their RTR?
I had burned two 270's before I bought the RTR 8. My 8's 270 lasted almost 4 tanks of fuel at break in before it just quit. I think I have been lucky, cause I put an Air 94357 in and had no problems. A few gallons later I found this website and the only things I did were: (1) check alignment of throttle linkage (I automatically do this on any vehicle), and (2) made sure there was still a few mm of carb travel after the servo is at wide open.

Like I said I have been lucky. I am at 6 gallons of fuel with the stock motor, but everything else has been upgraded. Good Luck. I love this thing.
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Old 05-13-2007, 06:49 PM   #3468
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Chris ,you missed some good racing saturday night.How was your trip?
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Old 05-13-2007, 06:58 PM   #3469
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Quote:
Originally Posted by tex1
WOW!

Let me know when your trash pickup is. I'll even take it out for you.


Really, there are a lot of factors about these servos going out. The other prob is an easy to open carb setup. Some carbs, if they are out of line just a little, will not open smoothly.

If you have an RTR the problem is most likely the carb. I have cleaned out every one we have sold. lubed up the slide real good, cut the throttle return spring, put a button head screw on the pull arm rather than the set screw to get the pull spring straighter and then checked alignment to majke sure it is right.
Only then did the normal stuff come into play like EPAs and grommets on the servo.
It is a good idea to put a small fuel tubing on the pull side of your throttle linkage. Let the throttle servo have this extra little bit of padding in case the chassis twist while you are WOT. It will not allow your throttle servo to strain.

Hope this helps.
TEX

Do we need some better pics?
The oring under the radio tray?? Come on... Losi is better than that!
TEX- Could you post a pic of this setup? Or send in email? desireegianna@yahoo.com
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Old 05-13-2007, 07:22 PM   #3470
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here is the pics guys....i dont know if i miss something about the setup
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Losi 8ight building and setup-p5140005.jpg   Losi 8ight building and setup-p5140006.jpg   Losi 8ight building and setup-p5140007.jpg  
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Old 05-13-2007, 07:27 PM   #3471
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Did you cut down the throttle spring. Looks like you have the old long ballcup on the throttle.

And its not just about setting endpoints. I have run a few 1/8 scales and had my first servo failure at my last race. I had about 90 minutes of runtime on my 8b and switched to the 8t and killed it after 15 minutes. The only diff was I didnt use the spacers in addition to the rubber mounts to raise the servo. That servo had about 6 gallons of runtime.
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Old 05-13-2007, 07:35 PM   #3472
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Quote:
Originally Posted by tomdav
Did you cut down the throttle spring. Looks like you have the old long ballcup on the throttle.

And its not just about setting endpoints. I have run a few 1/8 scales and had my first servo failure at my last race. I had about 90 minutes of runtime on my 8b and switched to the 8t and killed it after 15 minutes. The only diff was I didnt use the spacers in addition to the rubber mounts to raise the servo. That servo had about 6 gallons of runtime.
yes i did cut the spring about 3mm...
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Old 05-13-2007, 08:38 PM   #3473
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Personally,I run my carb with the ball rotated down a little more than that to clear the diff. I set my high epa by taking the filter off.Then I set it to where the carb is not quite fully open. I then make sure there is a little play left in the carb when at full throttle by pulling on the carb barrel.

I set the brakes to where they will barely stop the car on the bench.Then when I go to the track I set them where they will slow the car on the long straightaway.The car does not need to lock the tires up to work well.

Hope that helps
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Old 05-13-2007, 08:42 PM   #3474
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Well I have followed the directions given for throttle setup and I haven't had a problem as of now, but I've only put like 3-4 tanks on it on the street. I am running an ACE 1211 I believe on THR and a JR 8417 on STR. Are people frying servos only on the track? Like where there is chassis flex? or like also just running on the street? I plan on hitting the track sometime this week with it. I am sort of worried about blowing a servo :S I am not running servo grommets since I didn't get them when I got the car (got it used) BUT I am running rings of fuel tubbing as grommets. I've done this is the past with the TTR S3 and XB8 and never really had any problems with it. You guys think it's fine?

Tex,
When I got my car there was a piece of fuel tubbing on the pull side of your throttle linkage. I just took it off as I thought he had it on there as a gauge to show where his stop was set or something? I left the links pretty much the same but I did take the tubbing off. I want to put it back on now but I don't understand how it would take the strain away if it is put on at the end of the link after the stop. Because wouldn't the stop like not move anyways since it's locked in with the set screw? Can you help me understand the theory behind it a bit more please? I'm puzzled LOL
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Old 05-13-2007, 09:01 PM   #3475
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Quote:
Originally Posted by tomdav
Did you cut down the throttle spring. Looks like you have the old long ballcup on the throttle.

And its not just about setting endpoints. I have run a few 1/8 scales and had my first servo failure at my last race. I had about 90 minutes of runtime on my 8b and switched to the 8t and killed it after 15 minutes. The only diff was I didnt use the spacers in addition to the rubber mounts to raise the servo. That servo had about 6 gallons of runtime.
Tomdav- Is there a new ballcup?
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Old 05-13-2007, 10:33 PM   #3476
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I think Tex is giving an example of a shur fire way to pad the throttle pull in case of chassis flex at full throttle...

1. I run JR servos and the make the 270 that comes with the throttle for the RTR... That being said, I wouldn't run it for throttle in a gas truck, it's plastic from top to bottom. Just not a good servo. I know it is hard to swallow, but purchase a good servo with some torque and metal gears. Those who have gone to higher torque and speed servos have been experiencing less problems.

2. I see a lot of guys complain of the throttle servo woes and when I look at the car for them I find a lot of buzzing servos at neutral. Use a throttle return rubberband or oring and take that neutral load off of your servo. Then, the return spring on the linkage is just extra insurance.

3. Use the grommet inserts that come with your servos guys. Make sure your throttle linkage isn't hitting the top of the servo case on the throttle linkage side. If it is you'll see the mark were it has rubbed. Shim up your servo horn a little.

4. Grind a little off the backside of the top center diff mount plate. This allows you to rotate your carb back a little more inline. Grind a little off the front of the battery box section where the throttle servo ears are. This allows a little more leeway in a chassis flex situation.

As for the steering servo issue, I have only heard of one steering servo blown in this car and it just so happened to be a sponsored Losi driver... It wasn't the servos fault, seems as though some dirt and sand got in on the servo saver pieces and didn't allow it to do it's job. Most of the problems I see are due to carlessness or maintainence. I'm on gallon 4 and have had zero issues. I run 1 oring under the battery and the KingHeadz stiffener and all of the modifications explained above. This car is great, take your time with it at home and you will enjoy your racing at the track... Just my $.02
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Old 05-14-2007, 06:03 AM   #3477
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Trebor - I'll take some pics at the shop today. I'll do a whole RTR and show you guys what I look at and why. I have already told Losi about the problem.
Maybe we can get it stickied up top.

A_Stratus - The fuel tubing will stay stiff while you are in normal throttle open mode. When the chassis flexes like if you are tumbling and trying to recover, the fuel tubing will allow for this without having your radio tray move or opening your carb more. It will not strain your servo any more than using your brakes.

Leaving your carb a little closed is a bad idea. You will be inconsistant on your jumps. You will have different throttle input every time you corner!

Oring under your radio tray is a bad idea. Same thing. Plus you stress the plastic on the battery box. Don't like the idea that the battery box/servo mount controls how much throttle input I have.

My advise -
1. The 270 servo is very bad for this application. It is plastic and hard to pull closed.
2. Get you a good coreless motor servo like a Futaba S9451. Use the grommets and inserts! Core motors can pull more power and burn up the comm inside. Hince your motor goes bad.
3. Put a throttle return pull spring on your linkage.
4. Have some over extension play by running the fuel tubing on your throttle side. Put it in between your arm and the pull collet.
5. Set your carb to just open. (some will have extra travel and some will not) If your chassis flexes at WOT you are only collapsing on the fuel peice. Think about it. On the brake side you are collapsing two and we have been doing that for years. No problems there.

I just put my camera on charge. I'll put some pics up soon.

BTW - Who ever posted those pics looks like there is a washer between your throttle linkage and oyur servo. If that's the case then there is your problem. Your linkage is dragging on the top of the servo case. Not good.

This is my .02.
Hope it helps,
TEX
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Old 05-14-2007, 06:41 AM   #3478
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Archy, another thing u can check is the rear break wire. On mine i can see scuff marks underneath the center diff top plate. I bent it a little so it wont rub the plate.
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Old 05-14-2007, 08:11 AM   #3479
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Quote:
Originally Posted by Laysander
here is the pics guys....i dont know if i miss something about the setup
remove the washer that is under the servo arm. that will cause more drag on the linkage.
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Old 05-14-2007, 01:09 PM   #3480
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Hi there
My name is Nuno Im from Portugal and new here at the forum, nice one by the way.
I have one Losi 8ight and have been reading this thread.
IŽm having problems with oil leaking from the shocks so I bought the Ultimate products o-rings that were recomended by some users in this forum. The problem is that in the package it says "new o-ring goes in first, then the teflon bushing, then the old losi o-rings last". Is this correct? Should I use the old ones too? I think that way is going to be a lot of o-rings.
Can someone tell me exactly how should I install them(what goes first, number of o-rings used, etc) because I never done it before, Im fairly new in R/C.
Thanks a lot for your time
Best regards

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