Older, maybe late 80's early 90's gator 4x2

I have an older gator, bought used. recently have had issues with it stalling out when put in gear or after idling a few minutes.
Changed fuel pump & filter, blew out lines. Has been with a local mechanic for the past month & 1/2 "waiting on a part" finally came in today and still won't run. Of course can't get a hold of him again now. Have come this far but might be easier to pay for the part & take it to a JD dealer.
Any thoughts as to the issue.
where would I find the model number? I don't have any paperwork on it

thanks