3 wheel EZgo troubleshooting

[TheOldMan]

I do believe that's it! I'll get some pix in the AM. Can you give me any insight on how to set that bellcrank?

[JohnnieB]

I'd make sure the pot is good before doing any mechanical adjustments.

I've never even seen a pot-box throttle, but here are a couple things I picked up here on the BGW forum.

Looks like there are about four things that can be adjusted, so I'd mark everything As-Is and take a picture of it to refer to.

[TheOldMan]

KERNAL - I was wrong. The S/N is 857644 - guess that makes it an 85. Sure is in good shape for being that old! Mfg Code D2295.
JOHNNIEB-your diagram is exactly what I have. I removed the whole control box assy to the bench where I could see what's happening. About the first 15 degrees of rotation, the pot reads 0 then it begins to read very smoothly up to a max of about 16K. The lower end of the pot and the wiper are tied together, so my theory is that there has been an internal arc at one point that has burnt away the resistive element on that end of the pot, so one reads from that end, through the connecting wire to the wiper, until the wiper gets beyond the open spot, then it works correctly. However, the cart spins it's wheels as soon as it starts to pull, so I guess the starting resistance is much to low when the wiper passes the open spot. Before removing the control box, as you're latest suggested, I read about 15K across the pot with the throttle fully depressed.
Stamped into the back of the pot cover are a lot of numbers: PMC98191, CM44675, 20 9514. If that last set of numbers indicates 20K, that would seem about right, taking into consideration the open.

[scottyb]

1985 cart is a resistor coil speed control unit? Must be some mistake there what are the last 2 digits of the manufacture code? That's the year it was made.

The pot should operate in 0-5k range when mounted in the cart.... not sure why you read 3 Xs that unless you are over rotating it.

[yurtle]

Can you tell whether is a wire wound pot? If so, does it have a "wearable" wiper, like a motor brush? I have wire wound pots that have replaceable brushes, both rotary and linear. Some of them are as old as I am, and work as well as the day I got them. Is it possible to hit it with contact cleaner, or is it sealed?

Inquiring minds want to know.

[yurtle]

The reason I think it could be wire wound, is a throttle pot gets moved a LOT compared to the old-school pots on TVs and stereos, which probably get moved a lot less per day, and will eventually wear out.

[yurtle]

Originally Posted by scottyb

1985 cart is a resistor coil speed control unit? Must be some mistake there what are the last 2 digits of the manufacture code? That's the year it was made.

It's probably not unreasonable for a 29 year old label to be hard to read.

Are the label letters raised? If so, maybe it could be rubbed with a pencil. I complete washed away my motor data when I cleaned it during a rebuild.

[JohnnieB]

The corrected serial number given (857644) returns this on the EZGO Serial# look-up site.

Congratulations!
You have successfully selected your vehicle.
Make: Marathon
Type: Electric
Model: Electric 3-wheel Marathon
Year: 1994

[TheOldMan]

Further research tells me that all EZ-Go pot box controllers used a 5K pot. The Curtis replacement pot shown on one of the parts websites has exactly the same numbers stamped in the back of the case as the original, except the last 4 digits, and I'm going to assume that's mfg date. Looks to me like this is a 45 degree linear taper pot. Std old off the shelf item. Definitely not wire wound, or anything exotic. Can't understand why these guys want $20-$40 for one.
This one is no good anyway, think I'll open it up and see if my theory is right. Don't understand how it got from 5K to over 15K.

[JohnnieB]

I believe you have a 1994 model X-440 3-wheeler.
Picture at top of page C-1 in the attached parts manual.