shadows2013

hey everyone I have a quick question for everyone . I recently got my first airboat up and runnning . It runs good but im having problems with my throttle setup. It has an O.S. 46fx on it. Heres the deal , Im trying to use the servo to control the idle so that in the event i know its gonna roll i can use my transmitter to shut off the motor so i dont damage the motor . Im using a pistol grip controller so what would be the brake function works great for this . The problem is that either the servo or the cable isnt good enough to hold a consistant idle . I trim it out to idle good then over the course of a run it either idles too high or stalls . I can cure this by using the idle stop screw on the carb but then i cant shut it off and then also the servo is up against a solid stop ( the idle screw) .So my question is does everyone run the idle off the servo and i just need a better servo and cable for consistancy or should i just use the idle screw on the carb and if that is the case than do i need some sort of spring setup(similar to nitro car setups)so that the servo isnt up against a hard stop? I hope this all makes sense

saleens7

you should be able to shut down the engine by pushing the trigger forward instead of pulling it....this should close the carb and shut down the motor...

shadows2013

that is exactly how i have it set up but either my servo or the cable is so inconsistant the every time i move the throttle the servo stops in just a little bit diffrent of a position so i either end up with a stalling problem or a racing idle problem

RS 38-40

My Feedback: (3)

Not knowing what you are using for a cable or push rod you should be sure there is no slop where it connects to the servo and carb . If you are using a golden rod type push rod be sure that the ends of the outer tube is secured at both ends and you don't have any slop at the servo or carb . I use the servo to kill the motor with the brake on the TX .

shadows2013

i have epoxied the ends of the cable in but i think when i go full throttle the servo has a little more in it and it pulls the cables a little bit.

crispyspa

I, Like RS 38-40, use the servo to set the idle and the brake function to kill the engine. I too have the problem that you are having, but it's not as pronounced as yours seems to be.

Here is how mine runs:
Pull to full throttle and let return to center = "high" idle
Lightly tap the "brake" and let return to center = low idle
Apply brake fully = kill engine.
the difference between High and Low idle is about 300-500 RPM.

I think that this may be a more common problem than we think, I just make sure all the links are as tight as possible and use trim to sort out the rest.

TERBObob

My Feedback: (21)

If your servo is pulling further than your allowed room for the cable , then you need to either change the servo horn to a smaller one , of use one of the different holes in eithe the servo horn , or the throttle control horn .
Once you do that , and get the proper throw on the servo , your problems will be resolved .

shadows2013

thanks for the advice everyone.