I had my ST-15 out to day and when ever I hit the brake it wants to stall out and I have to let off. But if I adjust the idle anymore it will take off on me. What should I do?

If your motor has a throttle stop, you should adjust that. Thats what I did to fix my problem w/ my overdrive st.

When you say "adjust the idle" are you speaking of the actual idle screw (throttle stop as madblunted noted) or are you adjusting your LSN?

If you continue to hold the brake, does it continue to bog as if it were in a bind?

The reason I'm asking is you may have a clutch problem. Like it's too free and not slipping enough. But there again, it could just be in some carb adjustments. I need a little more info to go on.

Who needs brakes???? All they do is slow you down. Actually, does the ST-15 have a slipper clutch because I heard that they didn't for some odd reason...

I adjusted mine by first adjusting the throttle stop 1/8 turns, (BTW it took like a tank of gas to adjust it) I would run it, warm it up on that setting, and then pick the truck up and slowly apply the brake, and if it was going to die, I would adjust the stop a little more, run it and do it again, Oh yeah make sure your throttle trim is set up to where you want it, and just do this over and over then eventually you will have it adjusted so when you hit the brake the truck will not die! Then you will be skidding your truck around everywhere, and if yours is like mine it will make the truck screech a little which sounds cool. (I have proline speed hawg IIs which may be why it screeches)

First whats the throttle stop? When I adjust the idle to much it wants to take off. If I adjust the throttle trim anymore it will take off. And the low speed needle is wear it needs to be.

the throttle stop is the idle screw. it sounds like you have the throttle position so that its above idleing when the servo is at idle position. adjust the trim so that it doesnt apply throttle at neutral.

It is! But when I hit the brakes it cuts out.

well then it must be the clutch like billyman said. does it sound like its under load when you apply the brakes? does it move when it idles?

I doesnt move when it idles, you know when you cut out a lawn mower engine? it sounds like that.

like its flaming out? take you air filter off, turn on the radio and controller. and look at the opening in the carb as you apply the brakes. is it closing any when you do this?

Yeah it closes all the way. But there is a problem with my reciever now! I'm never running it in the snow again. Plus I jacked up my stearing servo two. This is after 11tanks in rhe snow. It sounds like your stopping gas flow and thats what its doing. How do I fix this?

first you need to adjust your throttle trim untill it closes all the way and adjust you idle screw untimm it opens the carb about 2mm. then make sure that it doesnt close still when you apply the brakes. if it does do this again untill it stays open about 2mm all the time.

2mm is kinda big, maybe 1mm would be better, youll have to adjust it further when you run the truck.

I'll try that when I fix my electronics.

ya snow and electronics dont mix.

Expecially when there not waterproofed that well. I used duct tape instead of sandwich bags and duct tape.

use a balloon on your reciever, another thing is you could simply have a to lean needle setting on the lowend, i would righen that up a little, also, shut the carb as far as it will go in, if the idle isnt the problem then it has to do with the gears, if the gears are the problem then just take it apart and replace them accordingly

um he already found the problem.

i use shoe goo to waterproof my electronics! i love that stuff. put it around all the seams and youre waterproofed. except for where the wires go into the receiver so i wrap duct tape around that.

if you say that if you adjust it too much it wants to take off, then you are adjusting to the wrong end. You don't want to increase you idle, you want to lower it. If you lower it, I can't see it wanting to take off. Maybe I am not understanding you? Your idle speed affects you clutch and then the drivetrain, the brakes are on the drivetrain. So you solve the problem by first removing power from the drivetrain, by lowering the idle and reducing the clutch engagement.

I have the idle right were I want it. Kinda running high. But I'll figure this who thing out.
I havent figured it out yet.
How could it be the gears?

well, if a gear is missing a tooth or something then when you hit the brakes it stopps the diff, then if your engine has too high of a idle it will keep clutch engaged, which will make your gear mesh jam momentarily, that will cause your engine to stall

so my suggestion is to just richen the engine up a little, or if it is tuned ok then lower the idle while the engine is running, if that aint it then it has something to do with the drivelines

AND MAKE SURE your servo isnt holding the throttle open any, then when you hit the brakes it kills out the engine, turn all your radio stuff on and then look in the carb, hit the brakes, if the carb moves then its set up wrong

All the gears are good. I pretty sure.

how does it sound when it stalls? is it cutting out instantly or does the engine slow down first?