This started yesterday…I push on the accelerator and the car starts to move forward to about 15 MPH then the speed starts dropping off to about 10…I have the Ride 4 Fun 7.5 motor and my top speed before all this started is about 40…Code 81 is the speed sensor or wireing.Not sure if the speed sensor is built in the motor.??
The speed sensor is in the end of the motor with the thin wires.
Daniel
I have a 2007 GEM E4 with an Error code 81 indicating the speed sensor is bad. I have replace the sensor and it did not correct the problem. The magnet is good and the batteries are fully charged. Any ideas?
RFF does offer tech support for their products. Some settings may be different with the larger motor.
I THINK the later model GEMS (post 2004?) had a “hardwired RPM limiter” on the motor controller preprogrammed to prevent overspeeding the vehicle past the federal limit of 25MPH for slow speed vehicles. To make this determination the controller uses the speed sensor to determine RPMs.
With a bigger motor, you can go faster - up to the predetermined RPM speed which then prevents the motor from going any faster. It seems to me that the workaround was to remove 2 of the 4 magnets in the speed sensor which “fools” the controller into thinking the motor is only running at half-speed and therefore it can exceed the RPM limiter.
I agree with GEMMechanic that you need to contact RFF for tech support at this point.
Al
[quote=ARandall;22992]I THINK the later model GEMS (post 2004?) had a “hardwired RPM limiter” on the motor controller preprogrammed to prevent overspeeding the vehicle past the federal limit of 25MPH for slow speed vehicles. To make this determination the controller uses the speed sensor to determine RPMs.
With a bigger motor, you can go faster - up to the predetermined RPM speed which then prevents the motor from going any faster. It seems to me that the workaround was to remove 2 of the 4 magnets in the speed sensor which “fools” the controller into thinking the motor is only running at half-speed and therefore it can exceed the RPM limiter.
I agree with GEMMechanic that you need to contact RFF for tech support at this point.
Al[/quote]
I guess I wasn’t clear. The vehicle is original with no upgrades. Have owned it from new and have replaced 1 speed sensor in the past (5 hp motor) and solved the problem. 2K miles later (and 3 years) the same code has came up and I purchased a new sensor but this time it did not solve the problem. I turned off the main switch to see if a reset would work and to no avail. Thanks for your responses.
It’s possible you got a dud. Unplug the sensor and try the cart. Other than having a slight accelleration delay the cart should perform to the maximum power settings programmed in the controller.
If push comes to shove I have a known GOOD sensor off a burn out you could try.
I am curious since you bought it new 1) how you previously got 40MPH out of a stock GEM “with no upgrades” and 2) why you replaced the OEM 5hp motor w/ a 7.5hp RFF. That seems like an expensive swap without being considered an upgrade. Did you reprogram the controller somewhere along the line?
Al
Hmmmm
We have 2 posters here 1 has a stock motor the other has a 7.5 RFF
I just recently got the same thing on my 07 E6. Pried the speed sensor of the find a broken magnet. Super glued half the magnet back on and viola no more problems and she runs 30mph now haha!
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