just bought a rtr matrix tr arena rtr.. very excited about it.. having a problem.. throttle servo is acting funny.. ill give the truck gas and it takes it sweet time going to idle when i let off the gas.. it acts like it isnt strong enough to go back.. i have to hit brakes to set it back to idle.. tried messing with linkage.. no luck.. so im assuming the servo isnt strong enough?? some advice would be great.. cant wait to go racing

that servo is slow when you only run 4.8 volts if you switch to a reciever pack which is 6 volts you will notice a difference

so you have heard of this problem??? does the pack make that big a difference or should i buy another servo?

Both! Get yourself a 6vlt pack and upgrade to a faster servo for faster throttle input!!


You can get by with the stock servo but why just get by???

I don't think this is necessarily a servo or battery issue. It may well be, but from the description of the issue, it sounds like there may be a slight maladjustment of the throttle linkage causing the carb not to be completely closed when returning to idle. A stronger servo will help, but I expect you can get it working properly with the stock equipment (which would be a good idea whether or not you plan on upgrading). Always first recommended RTR upgrades are the RX battery and the steering servo (throttle can normally be left til a bit later, you don't need a particularly strong servo on the throttle, especially if you have a decent battery), as the others have correctly said. Truggies especially need strong steering servos, it makes a big difference to how they drive.

PS Also worth mentioning is that after a fast run, the engine is supposed to 'high idle' for a few secs, this is not in itself a problem.

i havnt brought it past half throttle.. i already checked linkage

What you need to look out for is when you leave the throttle (do this without the engine running and with the filter off), while looking inside the carb, that the carb closes as much as it can (there should be a 1.5mm-ish gap). If it does not, adjust your throttle linkage so it does. If when you then apply brake, the carb closes a little bit more, then the linkage needs adjusting. This would not necessarily affect forward movement. It's unlikely that the servo is either too weak to center or centers so badly.

i did... adjusted the linkage and then i wouldnt have brakes because of the adjustment.. when i reset it back to where it was i have brakes and servo takes it time reseting.. if im driving and tap brakes it lets off gas and goes to idle..

Then you need to tighten the brakes. A new battery or servo will not help you with this problem, you need to figure out how to set the throttle up properly. You see the collars on the linkages, you need to move them appropriately. Do whatever you did to fix the idle, then simply tighten up the brakes.

cant.. when i set the linkage.. the spring prevented the servo from going back to brakes.. i couldnt win either way.. i even messed with brakes for hours yesterday

There must be a way, can you post a pic of your throttle linkage from overhead? Don't worry, we'll get this sorted out.

will post one tomorrow.. wont be home till late tonight

you need to loosen up the spring slightly so that it will allow the servo to brake if that spring is tight whne the servo is in neutral it will never allow the servo to brake because it is keeping the servo from moving.

no it is not a problem all servos are slower when you only run 4.8 volts but when you run 6 volts you will get full potential out of them and they will be faster

The stock RTR servos are pretty slow, but they are very strong (torque). I rigged up a throttle return spring to be a manual "failsafe" and to speed up the servo a bit. It actually helps..but the ultimate is just to get a better servo.
Good luck
Tom

Yeah notch likes hi-tec servos in his monster---- i think its the titanium 300oz one

bought a traxxas 2055.. they have always been good in my revo.. will let you guys know how it works... also bought a 6 cell pack

KEEP IN MIND THAT NO RECIEVER BATTERY PACK SHOULD EXCEED 6.0 VOLTS
NOTCH