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Old 05-08-2009, 09:36 PM   #1
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Default Servo failures

So I got a losi 8t about 6 months ago and it is the bomb. During break in however, right as I finshed tuning the HSN and finally got the top end speed going, the throttle servo failed at wide open. It was about that time I had wished I had put on the throttle return spring. I finally found the truck trying to climb a fence about 1/4 mile away from where I was running it, which BTW was a shut down car dealership with a nice big parking lot. That was after it jump two embankments and ran across 4 lanes of traffic then through a gas station parking lot. It feeeeeeriiiiiideeee the clutch, but came away pretty much unscathed. Guess everyone has to go through that at one point...

Anyway, I replaced the stock spektrum servo with a JR z590m metal gear servo, and after about 4 track visits, it failed right as the first heat finished in my first race. Is it something I am doing wrong, or just a freak occurance? BTW, just for shits and grins I called JR to see if there was any warranty on it, and the guy asked me for my address and said he would ship one out to me ASAP so I could get after it. Talk about service!!

BTW, running the stock spectrum receiver, sr3000 I believe, and a Spektrum 2.0 radio if that matters.
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Old 05-08-2009, 09:42 PM   #2
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You need to set your EPA so that the servo is not pulling the carb all the way.

I'll see if I can dig up the manual page that explains how to do it.
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Old 05-08-2009, 10:01 PM   #3
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Quote:
Originally Posted by pyromania View Post
You need to set your EPA so that the servo is not pulling the carb all the way.

I'll see if I can dig up the manual page that explains how to do it.
+1...........EPA on both throttle and steering servo.
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Old 05-08-2009, 10:18 PM   #4
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You don't really need your throttle servo to open your carb 100% to get WOT on nitro engines. As the others said check your EPA and make sure it's not pulling too hard on your carb!
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Old 05-08-2009, 10:19 PM   #5
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Dude if there is a track around your are go to it and ask someone to help you set up the linkage. If the linkage is not set up correctly it WILL continue to kill servos.
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Old 05-08-2009, 10:30 PM   #6
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I can't seem to find it.

Anyways,

When you pull full throttle with the radio, you should still be able to pull the carb another 2-3mm by hand.
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Old 05-08-2009, 11:02 PM   #7
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Not your servos fault & not how you set your linkage.Use the search function & see haw many hundreds of people killed T/B servos in the losi cars & trucks.Then see how many companys make radio plates to minimize that problem then look at losi ads & you'll see they say they redsigned the radio tray on the 2.0 for that exact reason then go on line to the losi site & find the addendum on how losi wants you to rig your car to minimize that problem lastly ask your self after all the info you found if you really think its something you did wrong.When I ran losi I thought these retards must be doing something wrong,after all I ran for over 4 month about 1.5-2 gal a month before my high end servo died(or was killed).But yeah first thing I would do is check your linkage setting against the instructions.Good luck with that
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Old 05-09-2009, 09:42 AM   #8
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Wow after that rant let me post something a little more objective. One yes there was a problem with the height of the 1.0 radio tray. Two not everyone had a problen. Reason being we adjusted our epa's and linkage correcty from the begining. Linkage should be inline and level not canted or angled. You may need to turn your carb a hair and adjust your ball linkage on the carb. To create a level and straight pull. Next take your air filter off. Looking into the carb. Your carb only need open flush with carb oprening. There is about 5-10 mm of throw past flush that should never be used. On your brakes if u apply brakes and your tray is pulling you have your brakes set to hard.

You are making a common mistake. A friend I compete against whom has a 2.0 burned up 3 Jr's because the linkage was not in line correctly. No need to diss Losi as the earlier poster every brand has a quirk or 2. Its the nature of manufactoring. If you should ever find the perfect trouble free car let me know I'll take 2.
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Old 05-09-2009, 10:25 AM   #9
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Not dissing losi just pointing out facts & where to find the fact I pointed out. I understand nothing in this world is perfect & all cars need a little tweak here & there. But a design flaw is not a quirk its a mojor problem in this particular case but horizion has an excellent warr program so kudos to them. I will happily admit that I have never been as fast with any truggy since as I was with my losi.My point in the post was not to flame losi or come here & pick a fight,but it just kills me when there is a glaring problem with the car & people blame the owner for how he built it & not the car.It seems to me that if you design a car that requires that much attention to linkage setup or you end up with burned up servos & still have some burn up even when set up perfect that in itself is a problem. BTW I have found the closest thing to a perfect car feel free to pm me & I'll let you know wich it is & the little quirks it has but I am still on the verge of picking up a 2.0 b just to see how they have improved it.
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Old 05-09-2009, 11:10 AM   #10
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Wow!

I am familiar with the linkage issue, and am pretty sure I have that right. I spent about 1 hour jacking around with it after the first servo took a crap, but will definitely go over everything again when I get the new one. In the radio tray addendum, unless there is a different one I hadnt read, it only talks about screw length in regard to the battery box, and replacing it with a shorter screw and orings to prevent the screw from jabbing the battery when driving.

Anyway, I can imagine if the servo is trying to pull still and either your brakes or throttle and they wont allow anymore movement, that can wear on it, so it seems the problem is fairly obvious. Thanks!!

I just thought of something else. I was having a hell of a time turning, and my DX20 is set up for my Losi and my Mutilator.....I wonder if I was driving it on the Muti settings?? GAAAKKKKKKK, I just went and turned it on, and havent driven the Mutilator since the servo failure, but it says ofn when i turn it on. I bet that is what killed it, SON OF A BIZNITCH!
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Old 05-09-2009, 12:14 PM   #11
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what i did was cut two coils off the throttle spring to take the stiffness away cause the spring is way to long and u have to compess it just to align it with the carb , im guessing u dint have the radio tray stiffer cause that really helps
and putting rubber gummets under the servo i do have my where there si only a little of the carb showing not wide open cause that was causing the tray to flex and i did put o ring underneth the battery box ,i did have to set my epa down to 60% cause if i go any higher it just stress the servo out . i still buzzes but its a diginal servo and it only does it a little then stops at full throttle i still have to set my brake linkage so it doesnt compress the spring so much.
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Old 05-09-2009, 02:53 PM   #12
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I had the same problem on mine. Blew two servos very quickly. Swtiched to a Hitech 7955 and have not had one single problem. Its $120.00 but no worries. Buy it now and be done with it.
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Old 05-09-2009, 03:24 PM   #13
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oh so thats why some servos are that much
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Old 05-09-2009, 11:41 PM   #14
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Quote:
Originally Posted by tc5 man View Post
oh so thats why some servos are that much
PLEASE have someone who runs a Losi set that up for you, and show you how to do it properly. I'd hate to see another racer pack it up due to the Losi servo issue, we need all the racers we can get!
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