2001 DS Club Car runs great then drops speed

Young_Buck

I have a 2001 club car lifted. I had the motor replaced with an upgrade by a local shop a few weeks back. it is an mcore system and the previous motor was the gray tin can i believe from GE. not sure what the new motor is. The car does about 19 mph per my GPS. twice now while out running the car it runs fine for several miles then the speed will drop to roughly 10 to 12mph then after a short distance drops to about 5 mph then to 2 mph, if i leave the car sit for an hour or so and hop back in it runs at full speed just fine again. It is a 48volt and i had the batterries tested with a duration load tester and the they maintained fine and the cart ran at normal speed after the test no problem. I am trying to figure out what the cause for the drop in speed is. kinda new to this so be gentle ... Thanks in advance for any insight....

BGW

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OLD MEC

My first thought would be a battery or two running out of power. I would confirm all batterys by doing hydrometer test on each cell in each battery and compare with STICKIES list in "State Of Charge Readings". I think you are going to find one or more weak cells? Use only a ( single float with temperature correcting scale. The hydrometer MUST NOT BE A MULTI BALL FLOAT antifreeze testers as it wont give you correct info.
You didn't say if you have a IQ ( rocker type switch F&R control under right leg ) or series cart ( lever type F&R under right leg )? This would help with diagnoses.
Internitant problems can be very hard as you must be testing while problem is going on?

Young_Buck

It is a series motor. As for the specific gravity everything read in good shape. I initial wondered if it could be a battery but when it ran fine at normal speed after leaving it sit for an hour and i did nothing to it other than let it sit and it then ran at the full speed for almost 2 more miles before i loaded it back in my trailer. that kinda changed my thoughts. i thought perhaps the control might have gotten hot and caused it to reduce speed or perhaps the motor had a short in the winding causing it to loose power as it heated up. any thoughts?

OLD MEC

Question have you done any other changes to stock cart other than motor? This would include 4 guage multi strand welding cables with crimped and soldered connections to replace all cables from motor, batterys, controller and F&R control, higher amp rated controller, change of F&R control to HD, larger diameter tires, rear seat, HD springs? Any of the above can put much heavier load on everything that could cause stock parts to break down or overheat? Just looking for possible weakness or reasons for your problem OTHER THAN MOTOR ITSELF??
To confirm your battery readings "BY GOOD SHAPE" on your gravity tests do you mean that each cell is 1.275 and voltage on each battery is 8.49 and pack voltage is 50.95? So often owners think that if batterys read near 8 volts they are fully charged and if total pack reads 48 volts its fully charged which is NOT TRUE so this is why I am asking for specific info on batterys? Not to doubt your tests in any way but if owners dont know how to do proper gravity test WITH CORRECT EQUIPMENT owners test results wont be of any true value. Please post your readings for forum to check if you have any doubts about results.
If battery readings show good and fully charged I think the next step would be to run cart until it just starts to slow down, then check for hot cables, connections, F&R control, controller, etc. Most will be warm but not a burn hot to your hand? This might give us some clues as to whats going wrong.

Young_Buck

The only changes that I have made other than the high speed motor are, larger diameter tires, lift kit, and HD springs in the rear. also added battery indicator light and headlights however the headlights have not been on at anytime during either breakdown.

As for the batteries I was not confident in my own battery testing skills so I took them to a battery shop and was informed that everything checked out and there was no need to replace any of the batteries at that time. that was just 4 weeks ago. not sure on the readings as I said not really familiar with testing and DC current. very versed in AC so I understand electricity just not overly versed in DC readings and such. I did check connections and the wires as soon as it stopped both times for corrosion, heat and poor connections and everything was in good shape meaning all connections are good there was no corrosion and the wires were cool to the touch not even warm. still running the stock controller and series switch. Batteries are US Battery, 6 - 8 volt batteries.

GLEEMO

Many times with motor upgrades , larger controllers are recommended , did the shop which did the upgrade recommend a bigger controller ?
Next time it happens , check for HOT spots , Cables, controller, Motor

Young_Buck

No they did not in-fact the selling point to upgrading to this motor was I would not need to upgrade my controller unless I needed more torque ie: for hills or additional people or towing etc...

GLEEMO

Which controller do U have , model ??? Curtis XXX ?
Did U keep U'r old motor ?

OLD MEC

Its very possible that the new motor is causing the stock controller to over heat internally because of higher than normal amp draw, and its trying to protect itself from burning up by cutting out? This can be caused by motors HIGH AMPERAGE DEMAND through stock cables, solenoid, controller, and F&R control, and yes even heavy foot over distances?
You in fact have pushed the ability for stock componants to handle the extra load caused by large diameter tires, lift kit, Hd Springs and give you what you wanted so NOW with a motor "that does not need upgrade controller" I think that what is happening is stock cables rated for 75 amps max in total lengths of less than 6', F&R control rated for 70-100 amps, solenoid contacts rated for 70-100 amps, and controller rated for only short periods at 225-250 amps is not able to take the load.

Young_Buck

No had to trade it in for core on th new motor. wanted some ridiculous amount for keeping it.