EZGO TXT speed issue already replaced motor and batteries

[genoz]

Hello everyone. I need some help with my 1999 36v EZGO TXT series cart. I live in a large retirement community and my cart \was very slow about 14mph. I got passed continuously. In an effort to increase speed I have replaced all of the batteries and installed 4g battery cables. I have also replaced the solenoid with an OEM model. I still wasn't getting any speed increase so I just changed out the motor with a D&D 170-006-0001 high speed motor. This increased my speed to 18mph. The motor was supposed to get me 22mph. After looking at the old motor I noticed that is was a model 73124G03 which supposedly has a top speed of 19.9 mph. Now What can be the problem? I also should mention that the cart has a back seat so there is some extra weight. I am driving on all flat golf cart paths. Is it possible that the speed controller is bad?

[JohnnieB]

What is the height of your tires? (Stock height is 18")

What is the max air pressure stamped on the tire's sidewalls?

Tires taller than stock reduce the amount of torque available where rubber meets road and low pressure tire take more torque to turn.

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Also OEM means Original Equipment Manufacturer, so are you trying to say the cart has a stock solenoid? If so, it is only rated for 85A and ought to be replaced with a 200A or higher rated one.

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Take another look at the specs on the D&D motor. (D&D website list the top speed as "up to" 19 MPH)

[genoz]

Thank you for the reply. The tires are stock 18s. I will check the tire pressure. I just tested the voltage on the batteries and the speed controller. The voltage of the batteries is 36.3 volts. the reading on the speed controller between B- and M- is 34.6 at full throttle. The speed controller looks different than the ones I've seem on this site. See photo below. Thanks for any more advice in advance!

[genoz]

Controller photo

[rib33024]

Are you sure the cart is a 1999?. It don't look like it. with that controller. Can you post the ser# and a picture of the cart

[genoz]

Im sorry. I just looked at paperwork and its a 2000. Here is a picture of the cart and serial number

[kernal]

That is a Curtis 400amp controller. Usually used in the shuttle 2+2 models of that era but as we have discovered on this board, they put it in some golf models also. Also I believe that is one of the high speed motors sometimes used so that should have been a 20mph cart from the factory at 36v. Don't know how rare but certainly not common.

Suggest you load test the batteries.
Regarding the solenoid. Usually these carts came with a bigger solenoid. 200amp I believe.

[genoz]

Thanks for the info. I just jacked up the backend and load tested the batteries. I get 37.3 volt at full throttle and 36.4 volts between the B+ and M- on the speed controller.

[kernal]

That isn't under load. get some clips to attach voltmeter probes to batteries. Drive cart up hill and note voltage drop. Do it for the whole pack and then each battery to determine if whole pack is weak or just one or more batteries. If no hills, you'll have to do it by mashing the go peddle from a standing start and note voltage drop.
Or take it to a competent shop that has the correct equipment to test them.

Make sure the cart coasts freely. No dragging brakes and such.

[JohnnieB]

Your batteries are not being fully charged. Ought to be 38.2V if Trojan brand or clones, higher for some other brands.

What is make/model of batteries?
What is make/model of charger?