I have a 65 200 6 cyl. It has the Pony carb carb. The engine was running great until it sat for about two months. The engine runs great until heated up, then stalls at idle and higher speeds. No problem cranking, but, it stalls. It was stalling last night and I really had to hit my driveway curb hard to make it up the driveway, then, the car ran great. The carb is about one year old. I have read over 200 treads and I cannot figure out what to do. I have ordered a new pvc and fuel pump. Could it be the float? Please help. thanks

 

Could be a clogged fuel filter.

 

Or sticking needle valve.

 

It's probably not going to be a clogged filter but its a weird failure mode. It it runs ok cold but not hot, it's also unlikely a float issue. You have a lean condition after the choke is off. It could be a vacumn leak or the idle circuit in the carb is contaiminated. Look for obvious vac leaks and if none are found you'll have to repair the carb(make sure to check the carb screws are set correctly before you tear it apart as it may be just an adjustment).

 

If you have any type of fuel additives (or even not), it has been sitting for a couple months, I would suspect the "varnish" effect since the fuel had a chance to evaporate (leaving the sticky stuff behind and undisolved or burned), you may just want to run some carb cleaner through the fuel for a tank or so. Mine turned to glue after sitting 6 months from some additive the former owner had in the tank. It was like honey.
You may have different parts sticking, so it wouldn't hurt.. If it was running fine before that, and you didn't change any settings before it started messing up, I would consider this first before trying anything else and maybe even change out *both* of the fuel filters. The float and needle could be sticking, just not all the time (heat expansion making it worse?).
I forgot what the additive is but it should be in the forums, if your car is going to sit for any length of time, you need to add it to the car to prevent fuel from gumming up your filters and carb.

I recently read this in the manual for my 1964. You can check if it is a clogged PVC system, with the car running, remove both the front and rear elements one at a time, if you notice a difference in idle, then it may be time to clean or replace your filter/valve/hoses. You'll know which one is dirty when the idle changes when that element is removed.. If it runs rough, then changes with the filter, hoses or valve removed, then that is the one that needs to be serviced. Don't forget to clean the spacer inlets at the same time.
Hope something here helps...

 

I would definitely try cleaning the carb since its been sitting for a while. Like MetalEd said, there could be varnish.

Was your carb actually new or was it a rebuilt one?

If your problem turns out to be the carburetor itself, then I would get a new one from Pony Carbs. My 65 had issues back in highschool when it was still a 6 cylinder. We went through rebuilding the carb and a few rebuilt ones from the store. I think the 4th one we got actually ran. It never ran right. After getting the new one the car ran nearly perfect.