hello all. working on a crown rc302040
ser # 1a222700

The machine is slow. Battery is good. Seems to be faster in reverse. Seems to completely quit sometimes when turning handle to the left. I'm aware of the switches underneath that slow speeds depending on which way you're turning. I just replaced the rear wheels on this machine and while I was under there I repaired the wiring on one of the switches and cleaned them up. But without a manual, what other checks could I do? Adjust the pot in the multifunction handle? Thanks.