jetplt

My Feedback: (2)

I have a rc10 gt plus and when I hold full throttle it surges on and off, and is lacking sufficiant power. All screws on the engine are tight. Pull starter fell off and I reattached it, wasn't sure if that had anything to do with it? Any buddy have any suggestions for a newbee!

Billyman

My Feedback: (1)

Sounds too lean. Richen it up a bit and you’d better do it quick because you’re on the verge of burning up your engine.

Also, check your fuel lines. Make sure you don’t have a leak anywhere resulting in fuel starvation or fuel tank pressurization.

And lastly, make dang sure you have a good seal at the carburetor itself.

jetplt

My Feedback: (2)

Thanks for the reply, I am pretty sure it is not running to lean. I was running it one day and it was running just fine and all of a sudden it started to surge. The servo itself was surging along with the engine. Then I noticed that 3 screws from the pull starter were missing and it was hanging on by just 1 screw. I thought that was causing the surge but when I finally got that wound back up and running again it still was surging. What did you mean by make sure the carburetor has a good seal. cause when I ran it again it loooked like it blew fuel out from around the carb. Thanks again I really appreciate your help I am still fairly new to the hobby.

Billyman

My Feedback: (1)

The carb has an O-ring seal. If you remove the carb you’d see what I was talking about. Sometimes they leak, which is bad. You said you saw fuel coming from around it….that is bad.

But.

If your servo was surging along with the rest of it, you also have an electrical problem my friend. It could be the radio, the receiver, the batteries, or the servo itself. When you pull the trigger on the radio, the throttle servo should go and stay plain and simple. I'll try and help you diagnose your problem as you check things and report back.

C_Watkins

My Feedback: (10)

Yeah, if the throttle servo is moving, it's not an engine problem. (unless something is loose on the engine)
Look for metal-to-metal contact. Remove it. Make sure to use plastic clevis for throttle,
make sure no metal is touching the head, etc... Alternately, if you find nothing else, I'd
begin to suspect you may have a bad servo, bad solder joint at the antenna, broken antenna
where it enters the receiver case, or a bad crystal.

jetplt

My Feedback: (2)

thanks for the info i am goingto try to start trouble shooting this weekend. I will let you know how it goes. thanks again

jetplt

My Feedback: (2)

hey i took apart the engine and checked all the seals and gaskets. it still surges. is there anyway to take apart the servo to see if it is defective. how much moisture does it take to screw up a servo? when all the electronics are on and i set the controller across the garage it seems to tick and slightly move back and forth, is that any sign of a bad servo?

Billyman

My Feedback: (1)

Does the steering servo surge as well? Check that. That could be a key element in diagnosing your problem. If your steering servo surges as well, then go back and re-read C-Watkins post and inspect thoroughly.

If only the throttle servo is surging, and you’re confident the steering servo is fine, swap the two. Make the steering servo the throttle and vice versa. If the throttle servo still surges (what was the steering) I feel quite sure you have a receiver problem. But it is possible there’s a bad channel from the radio.

If you have a buddy that might temporarily loan you his receiver (that is the same or is compliant to your radio) try that. Or, if it’s different all together but is compatible with your current servos, borrow both his receiver and radio and go from there.

If you can’t get a buddies stuff for trial purposes, let us know. I’ll think of something else to try.

jetplt

My Feedback: (2)

ok i moved the steering servo to the throttle position and put a new servo in the steering position. still surging? you mentioned there might be a bad channel from the radio. if so then what do you do to fix it? I must also mention that the car is only 4 months old. I guess to that i might want to by a new reciever as well, or try a buddies? thanks for the help!

Billyman

My Feedback: (1)

Which one?

It would have to be sent back to the manufacturer for repair. But lets try and eleminate that first. That's a rare problem.

I'll need you to anwer the "which one?" before we go further.

jetplt

My Feedback: (2)

i eliminated the original throttle servo and took the original steering servo to the throttle position and a new one in the steering position. does that help?

Billyman

My Feedback: (1)

K, so what was the steering servo is now the throttle and that servo surges too correct? So that makes two servos surging connected to the same slot on the receiver.

Your receiver will have ch 1, ch 2 and ch 3 slots. Each slot is a channel with a specific control from your transmitter (radio). Find the one that goes to your steering and then the one going to the throttle (leave the brake servo alone). Now reverse those two at the servo. What happens now is the wheel on you radio operates the throttle and the trigger operates the steering (the steering will only go one way). With any luck, the steering servo will now surge and the throttle servo (when turning the wheel) should stabilize.

This will indicate a bad or receiver or radio channel problem. Unfortunately, the only way to distinguish between these two as which is the perpetrator is to try another receiver and/or radio. This is where your buddies stuff comes in handy IF his parts are the same and/or compatible with yours. You don’t want to just swap his receiver with yours and then use his radio too. This won’t help determine your problem. You’ll need a receiver that works with YOUR radio and you’ll also need to use YOUR crystal.

Bad channels in radios are very rare but it’s possible. I’m still leaning toward your receiver.

RnT Racing

Do you have a fail safe installed?

I just installed one (Dynamite brand) and I started having the same problem (on the bench at least....haven't run the truck with it yet). I found that by turning the throttle HIGH ATV down just slightly the problem went away. In this cheapo transmitter there seems to be a slight detent (which I don't believe is supposed to be there) in the trigger action. It's like it is going to far.....past full throttle..... after I press past that detent or catch (whatever) then the throttle servo starts surging.

I don't know if this will help you but it just sounds like nearly the same thing.

Does your throttle servo surge when the engine is not running?...... or is it only when the engine is running?

Later......
Ron

jetplt

My Feedback: (2)

I just wanted to mail you back and say thanks for your help. It ended up being a bad crystal, put a new one in and I was back in buisness. sorry it took so long to get back to you, thanks again.

Billyman

My Feedback: (1)

The only thing that matters is that you got it fixed.