I was working on a friend's Team Losi XXX-NT (Mach .15 engine) today and had a bit of an issue. I was tuning it up for him, and while working on the high speed needle doing high speed runs down the street I realized that the steering servo starts to twitch significantly at high speed. I hold the car in the air, and pull the throttle on the transmitter, the car revs up (sporadically) and the steering servo moves side to side quickly. Also when revving up the engine either by remote or manually the engine peaks in rpms and goes wild even with the throttle off at idle. All batteries were replaced by fresh cells. I think the engine revs could be related to tuning but the servo twitches? No clue.

XR2i radio if it matters.

It could be bad crystals.>Had that,fixed that.<

they go bad or just mismatched pairs? works fine at lower rpm for a decent range too. just when the engine revs up high enough it'll keep up even at idle for a bit and the servos go crazy. then it all calms down if you hold the brake for 15 seconds. not a fun situation.

Yep,sounds like bad crystals.If its not bad crystals,there may be some metal to metal contact somewhere.(Did you ever notice that the servos twitch when you touch the heat sink with the glow plug ignitor?)

I did indeed.

I'll swap them out with my confirmed crystals tonight. btw, happy new year!!!

Glad I could help...Happy new year to you!

Look for a pinched wire or a bad connection at the reciever box[&o]

Antenna wire could be crossing a servo wire, or the battery wire and picking up interference. Or antenna wire could be touching the chassis.

bad crystals fix it before they totally go or its a bad radio / servo..... or someone tell him to check his remote antenna aswell!!!

its funny you bring that up, because he broke off the tip of his antenna on the transmitter.

tomorrow we're driving again and i'll put in my reciever and use my transmitter and see what happens.


any insight as to why the engine peaks and screams at idle? high speed too rich, leaving too much fuel in the case?

I am guessing you are running the stock radio. Check for any metal to metal rubbing together!

how close are you to the car when they twitch cause if your far enough away you could just be going out of range and also check the remote and make sure the antenna is screwed in all the way.(kinda obvious but i have made common mistakes like that before)