My Sacura will only go at full speed

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Hi, anyone know what is wrong with my wife's Sacura S305, (the one with the battery on the front of the frame). It will only run at top speed. I have totally disconnected the throttle twist grip and it still does it.
 
D

Deleted member 4366

Guest
Hi, anyone know what is wrong with my wife's Sacura S305, (the one with the battery on the front of the frame). It will only run at top speed. I have totally disconnected the throttle twist grip and it still does it.
Common problem: The controller is past it's sell-by date. Unless you know how to check, unsolder and replace FETs, you need a new controller.
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Hi, thanks for your advise, where will I find the controller please, and how will I recognise it? Jokemor
 
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Deleted member 4366

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36V/250W speed controller for E bike & scooter (brush | eBay
If you could take a photo and/or give a written explanation of the connections to the controller. I Could give a more accurate assessment of which one you need. E-crazyman above has a good reputation. You should e-mail him to ask if he can supply the controller with a pedal sensor connector. I believe he can. This one will probably give a little more power than the one you already have. Unless you use the specific sakura controller, you might have to solder/ change a few wires/connectors. Please say whether you have that capability.
 
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Deleted member 4366

Guest
36V/250W speed controller for E bike & scooter (brush | eBay
If you could take a photo and/or give a written explanation of the connections to the controller. I Could give a more accurate assessment of which one you need. E-crazyman above has a good reputation. You should e-mail him to ask if he can supply the controller with a pedal sensor connector. I believe he can. This one will probably give a little more power than the one you already have. Unless you use the specific sakura controller, you might have to solder/ change a few wires/connectors. Please say whether you have that capability.
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Thanks for that, I can solder, no problem, could you tell me where the controller is located, please, to save me stripping the whole bike down.
 

flecc

Member
Oct 25, 2006
53,601
30,869
The battery will be in the battery box or in the cowling just below it on the S305. It often takes the form of a small rectangular box.

Have a look inside the battery box and you'll see the black rectangular SLA batteries in there, it may be with them.
 
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Deleted member 4366

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Sorry, before condemming the controller, there's a couple of tests to do to confirm that the problem is in the controller itself. I had wrongly assumed that you knew where the controller was and had disconnected the throttle at that end.
You need to follow the throttle wire down, and it will lead you to the controller. You need to unplug it there and see if it still goes at full speed as soon as you switch it on. If you can, do the same with the oedal sensor. If it still runs at full speed, you need a new controller. If it doesn't, it could be the throttle.
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Throttle cable

Hi, thanks again, been away hence the delay. I have followed the throttle cable down into the housing across the handle bars. The cable ends with a small plug that is connected to a block inside this housing. I unplugged this but the bike still went flat out. Hope you understand this.
 

flecc

Member
Oct 25, 2006
53,601
30,869
I've read elsewhere that putting the key in and turning it backwards releases the whole battery pack from the frame, so the controller almost certainly won't be inside there.

Following the cable path in the photo below indicates that the second option I gave for it's location is correct, inside the cowling at the base, just ahead of the pedal crank:

 
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Deleted member 4366

Guest
Hi, thanks again, been away hence the delay. I have followed the throttle cable down into the housing across the handle bars. The cable ends with a small plug that is connected to a block inside this housing. I unplugged this but the bike still went flat out. Hope you understand this.
In that case you need a new controller - or someone that can test/fix your present one for nothing. The problem is likely to be blown FET/s
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Thanks

Hi Thanks for that, I assume the controller is the kit that the throttle is attached to, I will let you know how I get on.
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Hi, back from hols, I have stripped the crank cowling and found a component covered in black plastic for protection, it has 5 wires: Red, Brown, Orange, Black and White. The wires are attached to a white connector that also has another two wires that are connected to a capacitor about 2" long. Is this the controller? my guess is that it is, and is the capacitor standard? Regards, John
 
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Deleted member 4366

Guest
Hi, back from hols, I have stripped the crank cowling and found a component covered in black plastic for protection, it has 5 wires: Red, Brown, Orange, Black and White. The wires are attached to a white connector that also has another two wires that are connected to a capacitor about 2" long. Is this the controller? my guess is that it is, and is the capacitor standard? Regards, John
Does your bike have indicators? If so, that might be the components that make them flash. The controller is normally an aluminium box about 100x50x25mm with lots of wires attached.
 

jokemor

Finding my (electric) wheels
Oct 4, 2011
7
0
Hi, yes, it does have indicators, you can't really miss the speed controller can you. Any idea where I might get a replacement from, please?