Cushman titan 1998

[560farmall]

Looking for info on my Cushman Titan. Model 898352. 36 volt. This one has a tag. It has a fiberglass cab with fiberglass doors. Bedsides and tailgate. The operators manual shows the model number being a direct drive. This one is belt drive. The unit is in very good shape for a 1998 year. The manual shows two other models with belt drive. Both units are 48 volt. My tag clearly states unit is 36 volt. The motor tag is also 36 volts. All the wiring appears to be pretty much untouched. The curtis controller is a 24-36 volt 400 amp. I am just trying to fihure out what the issue with this unit is. The units approx top speed now is less than 10 mph. Looking for info on what or if anything has been changed. Unit came from a equipment rental dealer. Any help would be great.