Losi Truggy
11-30-2007, 10:06 PM
#811
I had one throttle servo failure so far....I'm not sure if maybe you guys have heard of/seen similar things so I'll go ahead and try to describe exactly what happened...
Futaba S9402 servo. Great working servo, never had any issues with it in any of my other vehicles. After a single tank of gas in the Losi it stopped working(just breaking in the engine in a parking lot...slow/steady throttle punches and applying the brakes). When I finished the tank of gas the servo got stuck in the neutral position. If I hold the trigger down to full throttle on my transmitter and push on the servo horn a little bit(to help get it started)it'll move all the way to WOT and I can go back/forth from about 50%-100% throttle without any problems. Once I come back to neutral it gets stuck again though. The same goes for braking...once it gets past neutral it's fine but if I ever come back to neutral with the servo it'll just stay there.
Since it still 'works' I'm thinking I might just have to take it apart and inspect it, but it might be salvageable. I was thinking the wires may have gotten wet or were getting shorted out somewhere, or maybe something is stuck in the gear mesh inside the servo somehow...possibly even a ruined gear or two?
Anyway...I put another throttle servo in the truck now (without changing any of the linkages or anything)and it's been fine for a few tanks of gas and I haven't had any troubles with it. So I don't think a bad linkage set up may have caused this but...from what people have been saying these Losi's are picky about how you set up the linkages. So let me know what you think. I guess it's hard to tell over the internet what exactly might be wrong with it...I'm just wondering if maybe others have had similar problems with throttle servos in these Losi trucks?
Futaba S9402 servo. Great working servo, never had any issues with it in any of my other vehicles. After a single tank of gas in the Losi it stopped working(just breaking in the engine in a parking lot...slow/steady throttle punches and applying the brakes). When I finished the tank of gas the servo got stuck in the neutral position. If I hold the trigger down to full throttle on my transmitter and push on the servo horn a little bit(to help get it started)it'll move all the way to WOT and I can go back/forth from about 50%-100% throttle without any problems. Once I come back to neutral it gets stuck again though. The same goes for braking...once it gets past neutral it's fine but if I ever come back to neutral with the servo it'll just stay there.
Since it still 'works' I'm thinking I might just have to take it apart and inspect it, but it might be salvageable. I was thinking the wires may have gotten wet or were getting shorted out somewhere, or maybe something is stuck in the gear mesh inside the servo somehow...possibly even a ruined gear or two?
Anyway...I put another throttle servo in the truck now (without changing any of the linkages or anything)and it's been fine for a few tanks of gas and I haven't had any troubles with it. So I don't think a bad linkage set up may have caused this but...from what people have been saying these Losi's are picky about how you set up the linkages. So let me know what you think. I guess it's hard to tell over the internet what exactly might be wrong with it...I'm just wondering if maybe others have had similar problems with throttle servos in these Losi trucks?
11-30-2007, 10:30 PM
#812
From what you describe I had a similar story with an airtronics 358. Exept my story continues on. I didn't check the clearance of the servo to chassis. My servo was resting on the chassis. I was at a new track layout with a very large double and I was one of a few that would hit the jump just right and clear the whole thing. Most would hit the first jump too hard and scrub all their momentum, ending up with a single-single. After lots of practice time and one qualifier my servo started working intermittenly just like you describe. The semi-sponsored driver I roll with looked my truck over and pointed out that my servo was riding on the chassis. DOH!! My bad. One day I'll send it in for repair. I wish I knew what was messed up with it. I would love to have it fixed and back in service. I'm getting short on servos. Too many vehicles. LOL.
11-30-2007, 11:51 PM
#813
Ya, I have not checked to see how close the servo is to the chassis. I will definitely have to check that out. If it is in fact on the chassis, or very close...should I simply throw some washers under all 4 servo mounting screws to bring it up a little bit? Unfortunately this Futaba servo is several years old and I know Futaba wouldn't fix it even if I did bother sending it back to them.
11-30-2007, 11:57 PM
#814
The spacers come with the RR and the RTRs. They are small, black, rectangle, plastic spacers. They go under the servo ears. So they'd be between the servo and the radio tray, lifting the servos up. check both servos when you pull the radio tray. It's too easy to do, so don't skip it. I'm not sure if the manuals mention servo spacing or not, but I don't remember seeing it. At any rate, the trucks are supposed to come with the spacers in a small back with a few other little items.
12-01-2007, 12:20 AM
#815
I don't have those spacers...(bought the truck used). I'll see what I can come up with though as far as some other type of shims or possibly a Losi part number. We'll see.
12-01-2007, 12:58 AM
#818
wait..wait..wait.. Did yours come with the O-rings to put under the tray? 
I set the linkages to push/pull the carb as straight as possible. I set the EPA's. And I use fuel tube on the end of the throttle linkage--to absorb the flex or extra movement. And I make sure the servos are not resting on the chassis when installed. Never used and of the other tricks/tips though. Mine do just fine. I've been pleased how well the Ace servos hold up to my abuse.
I set the linkages to push/pull the carb as straight as possible. I set the EPA's. And I use fuel tube on the end of the throttle linkage--to absorb the flex or extra movement. And I make sure the servos are not resting on the chassis when installed. Never used and of the other tricks/tips though. Mine do just fine. I've been pleased how well the Ace servos hold up to my abuse.I also use 2 aces 1015. I love theme.
I will take a pic. tonight after work maybe U can tell me if its set ok.
mzl Hellsavage
12-01-2007, 01:15 AM
#820
12-01-2007, 01:35 AM
#822
Hello fello zombie....nothing like the dark...
12-01-2007, 01:43 AM
#823
I made some pics I have everything up and running.
mzl Hellsavage
mzl Hellsavage
12-01-2007, 03:18 AM
#824
Cool Hellsavage. I have one more thing to add for ya. Is there any coil binding on that spring when you apply full brake? If so the spring needs to be trimmed slightly until there is no bind. Some have claimed this has caused servos to go out. And as long as the carb barrel gets pulled/pushed straight out/in you should be good to go.
Thanx for the pix. I've never seen the addendum for the O-rings before.
Thanx for the pix. I've never seen the addendum for the O-rings before.
12-01-2007, 03:53 AM
#825
@air8
Now that U mention it Yes she is binding a bit at full brake. I will cut it down Thanks man.
I use feul tubing for brakdisk spring. Instead of a normal spring. They can never get between the howl of the brakepad and the bold. I saw a guy throw away the winnings du to this happening. Just a tip.
mzl Hellsavage
Now that U mention it Yes she is binding a bit at full brake. I will cut it down Thanks man.
I use feul tubing for brakdisk spring. Instead of a normal spring. They can never get between the howl of the brakepad and the bold. I saw a guy throw away the winnings du to this happening. Just a tip.
mzl Hellsavage