Private message me a good email adddress and I will send you the manual for a 1985. It is similar to the 1986. A supplement for the 1986 can be found here:
http://www.buggiesgonewild.com/colum...UTILITRUCK.pdf
Between the two manuals and frequest visits here you should be able to handle just about anything on that cart. For whatever reason, 86 - 88 Columbias never gained much consumer attraction so not many exist. The good news is that those 80's carts are somewhat cool because it's pretty easy to exchange parts across manufacturers. Example, 80's Par Car carb = a few hundred bucks. 80's EZ-Go carb = $70. 80's Columbia fuel pump = $50. 80's EZ-Go fuel pump = $25. They all will work fine.
Don't let your neighbor BS you. Having to choke is just about always a "not enough fuel" issue. I mean, if it was a worn belt then why would choking have any effect at all? Getting more gas to the carb via choking obviously does nothing to help a worn belt. Good news is that, crank seals aside, fuel problems aren't all that tough to correct. A new / rebuilt fuel pump may do it. A lot of guys, me included, convert from the standard "vacuum" style fuel pump to an electric pump.
That said, it still isn't running quite right so, unless that cart has a pristine exterior, I wouldn't go more than $500 on it.