garrett, the carburetor has some lingering issues. i would suggest sending it out to be rebuilt.

it's possible this carburetor is not calibrated correctly for the engine application---it could just be a used carburetor some fly-by-nighter threw on it so they could flip it. so just exchanging it for a reman is not your best approach---you will just get an identical carburetor in return.

i would start with your local clark dealer. believe it or not parts and information are still available as there are many c500s still in daily service.

there are a number of other things you should be testing here, which i outlined in an earlier post that was clipped, but as i said then, this is all way beyond the scope of a forklift operator and because this truck is being used at your workplace, you can be held personally liable if this truck fails and causes an accident while under your care. If one of your co-workers loses an arm because a fork or chain snapped, if the brakes fail and you put it through a wall and into someone's chest, you get sued---or worse yet, youre the victim yourself---get the picture?

the best advice i can give you is to stop enabling your employer before your life gets ruined. it's not worth it.

good luck, let us know how you make out.