87 Electric Marathon Runs Slow

[oldgrape]

Howdy all. I just acquired this 87 Electric Marathon (36 volt). The frame is in pretty good shape. Not much rust at all. Batteries were bad so I just replaced all of them. Charged over night with the EZGO charger. It runs both forwards and backwards but very slowly. It may run about 8 mph. I did not replace the wires yet but I have ordered some. It has a resister coil so from what I read here I need to convert it to an ESC system. Will that get me going much faster? I would be happy with maybe 15 to 20 mph. Will I need to go to a bigger motor? I hope to put on a new rear seat and lights. But if I changing to an ESC won't add more than a couple mph then not sure if it is worth it in the long run. Don't care about the resale but not getting where We want with this cart even after many $$$.

Can anyone fill me in on what I can do and what the best end result I can expect?

yes going to ESC will increase your speed ... if your motor is not worn out ... stock was 12mph
first check the resistor coils if they are touching separate them ..
then check your sweeper arm and make sure it is making good contact with all studs ...the top one especially (#4)
also check all cables to coils
if all that is good then pull motor and check brushes

post 2x

[oldgrape]

Thanks. I'll check all the wires again. My coils are enclosed in a metal box like frame. Is the sweeper arm you refer to on the inside of that?

no ...

[oldgrape]

ok. Just figured out what the sweeper arm is. It does appear to hit all studs including #4. Seems to hit #2 & #3 a little better than #4. Also a good amount of rust on those 4 studs. Everything seems tight. The solenoid looks as if it has been there a while. The cable going from the solenoid to the swing arm looks a little worn. But then all of the cables look that way.

technically its a EZGO Foot Switch Wiper
clean studs with emery cloth also the Foot Switch Wiper Contact



it can be removed easily, if it is pitted or not even across the contact, replace it

[oldgrape]

Thanks. Will clean the studs. I may just replace the cable. Insulation pulled back completely at both ends.

[rlw]

Oldgrape,

Excellent advice from crash-test-dummy above.

I've got an '84 Marathon, similar setup. I took the wiper board (and arm) to a buddy's machine shop. He clamped the assembly in a milling machine and took off the top zillionth or so of an inch from the contacts. That made them all flat, clean, and in the same plane. He also milled flat the end of the wiper contact. Make sure you clean out any copper dust from between the contacts before you put the whole assembly back together.

My accelerator pedal is as smooth as a baby's behind now.

If you don't have a friend like mine, you can do a pretty good job using a fine-grit sandpaper on a flat edge of a workbench. Make sure you don't rock the wiper assembly as you move it back and forth over the sandpaper. The object is to get all of the contacts flat and in the same plane. It's a bit harder to flatten the wiper contact by hand, but it can be done. The object is the same, you want the face that contacts the assembly to be as flat as possible. That lets the maximum surface area make contact and carry current. If it doesn't ride squarely, you're putting lots of current through a small chunk of copper. That makes sparks and smoke and all manner of bad things can come from that! I know, my first attempt was sloppy and was part of the reason I had to take it in to my buddy's shop.

Hope this helps,

RLW

[oldgrape]

Thanks for the info.