throttle sticking

[Brad12]

title says it all, throttle seems to be messing up, whenever i turn to go faster it just goes to full, and i have to use my breaks to disable this... how can i fix this?

 

[fechter]

It sounds like the magnet inside came loose. There are different styles of throttles, but most common ones have magnets attached to the grip that move and a hall effect sensor that doesn't move. If one of the magnets came out of position, it could do what you describe. A broken ground wire could also do this with some throttles.

Most throttles come apart by removing a couple of screws. Some may have snap clips that are harder to take apart. If you get it apart, a loose magnet should be obvious. If the magnet is loose, it has to go a certain direction in the socket to work properly. Test first before glueing.

 

[Brad12]

Thanks, ill have to take a look at in tonight. so what am i exactly looking for to see if the wire is grounded

 

[dogman dan]

Fortunately throttles are quite cheap. Find one that ships fast.

 

[Ykick]

Has it ever worked properly? Does your controller have cruise control?

 

[Brad12]

it has been happening for awhile, but it hasnt been always doing this. i believe that my scooter might but not really sure

 

[d8veh]

It's one or the other. Some controllers have cruise control, which holds the throttle when you let go of it. You can test for this by blipping the throttle or operating a brake switch. If the throttle stays on afterwards, it's a displaced magnet, if it doesn't, it's the cruise control operating. If you have cruise control, but don't like it, you can disable it by unplugging a couple of single wires, which are joined with a connector at the controller. If it's a displaced magnet, you have to dismantle the throttle to repair it or get a new one.

 

[d8veh]

There's another potential cause which I forgot about. If the signal wire from the throttle touches the red 5v wire, then you get ful throttle. This can happen at the hall sensor legs if the cable has been pulled, or it can happen anywhere along the cable to the controller, where it might be damaged by squashing or cutting. So follow the cable along its length to see if there's any damage. Sometimes there's a little removable panel on the throttle to check the hall sensor, otherwise you have to dismantle the throttle AFTER removing it from the handlebar. This might help some people, but I'm going to bet that you have active cruise control.

 

[Brad12]

its not just cruise control because once i touch the throttle it just goes to full no matter what, and even when the hit the breaks it will still go when i let go of it

 

[Brad12]

I have opened the throttle and it doesnt seem to have any magnets or anything, just a simple spring. any other problems that could of occured? daymak themselves thinks it a controller problem

 

[fechter]

Some throttles use a potentiometer instead of magnets. These are rare. Pot throttles usually have some gears. Trace the wires inside the throttle and see what they go to. A hall sensor is a little black transistor looking thing with three legs. A potentiometer is a round can thing with a shaft sticking out that turns.

A really good test would be to use a voltmeter and measure between the throttle ground and signal wires. The ground is usually black. With the voltmeter attached and the power on, you can turn the throttle and measure the voltage range when turning. Of course you should disconnect the motor or lift the wheel so the bike doesn't go anywhere. This will tell you for sure if the problem is in the throttle or in the controller.

 

[Brad12]

so if the throttle reads what 42v? should be good if not a controller problem? still havent checked in the wire was grounded properly as it would be a huge mess to check on my bike

 

[fechter]

42v would be way too much for the throttle. Some throttles have a built in battery indicator which might see full pack voltage.

The actual throttle uses 3 wires. One ground, one 5v, and one signal. With a hall throttle, the signal voltage varies from roughly 1v to 4v as you advance the throttle. Most go a bit beyond this range. A pot throttle will go from 0 to 5v as you advance it.

If you are seeing 42v on one of the 3 throttle wires, something is seriously wrong.

It makes measurment easier sometimes to use the battery negative terminal for one of the meter probes. The battery negative is the reference for all the voltages. The black throttle wire goes to battery negative.

 

[Brad12]

Yeah i havent looked at it but i was just wondering? so how will i know the problem from the voltage? people were saying that the wire must not be grounded.. is that correct?

 

[fechter]

If you measure the throttle signal wire and it suddenly jumps to 5v and stays there ,then the problem is with the throttle. If the signal varies smoothly from 1v to 4v and returns to 1v when you let off, then the throttle is good.

Grounding the throttle signal wire could possibly blow the hall sensor or pot if you give full throttle.

 

[llile]

Mine did this when a throttle ground wire failed. Was intermittent for a while, then just went to full throttle all the time. Made for an interesting ride, one hand on the kill switch. Problem dissappeared when I replaced the wires.

Just replace the throttle, they are cheap and prone to failure.