It could be a glitch with the motor or RCA connection and we'll be glad troubleshoot it for
You.

But I would like to mention that we found out that the last customers that experienced this issue was due to that he was excessively lubing the machine causing the lube (non conductive material) to drip down inside the motor, clogging the motor and causing a the brushes to act erratic.
We opened his motor and it was full of oil.

If that's the case, leave the motor bolt without cam upside down for 24hrs and put some paper towels so they make contact with the surface where the oil will escape. This May or may not work as oil inside the motor really kills it.

One drip of oil is what you need every 50 hours or so. Anything more than that is exceed that will end up inside the motor.

Get I touch with us for further assistance. We'll be glad help.

Now regarding motors varying startup voltage, I'd say it's normal as this happens with freshly brand new motors too.






Gaston
FK Irons - Spektra Rotary
www.fkirons.com