Kymco Maxer 4U issues

[astroman]

Hello this is my first post here and i hope it is in the correct place.

Basically i have a faulty Kymco Maxer 4U and am looking for advice. The mobility scooter is about 2 years old and
suffers from a few "showstopper issues".  I have come to the forum since the local shop who supplied the machine is
clearly a "box-shifter" and has no service/technical skills to resolve the problems. He charged me $100 for a service in which he did nothing,
oher than spray WD40 on the axles , so i will have to sort it out myself.

The issues are as follow :-

1.)Pulling the forward and reverse lever does nothing for about a second or two before there is any forward or reverse motion. This is NOT how the scooter behaved when new. I mean there was no delay when the scooter was new.

2.)There is a lack of power and the scooter never seems to have full power although both batteries are new.

3.)One of the brushes appears to burn out very quickly and i have replaced it a few times, but the lifetime of the one located  brush seems shorter than the rest. I mean the brush in the one position on the armature seems to burn out.

I am a fairly competent electronics engineer and have had a quick look  "under the hood". All i really see of interest is a so called "S-drive" which i guess is a current controller for the obvious motor. The two batteries are wired in series and seem to deliver 48v , and seem healthy under load conditions.

My guess is it's the "s-drive" and it is not controlling the delivered current properly and perhaps it is damaging the brush mentioned earlier.

Sadly in the UK i see no sign of the service manual which would be very handy. I have heard rumors of a diagnostic device that plugs into the "dash" but have not seen any evidence of this physically myself.

Any help/guidance  would be appreciated

[souzamoto]

This forum is for Kymco Powersports products. I don't know of any Kymco Mobility Forums
 

[CROSSBOLT]

Yeah, well, 'lectric motor is still a 'lectric motor! One brush out of two, three or four on the same commutator wearing too fast is: 1. Wrong brush, too soft, wrong material not mated to commutator or in backwards. 2. Too much, too little spring pressure (way different than the other(s)). Now as far as the other tech stuff, I think we are all lost on that. It has taken years for us to sift through the wrong information in the scooter/motorcycle service manuals and dealer misinformation! You may wind up being THE expert on these things!