Can't remove jet needle

I took my carbs apart once again because the bike would not start without starting fluid and I had to replace my main jets anyways, also I did have fuel in each of the bowls. I was going to replace my jet needles with new ones but ran into a problem after I replaced the first jet needle. The second third and fourth jet needles would not come out because the screws inside the throttle valve are stripped from the previous owner. Is there any way to remove these screws?

I don't want to have to buy new throttle valves, also I wanted to change the clip position from 4 to 3. At least I think they are all at the fourth position based off of the only one I was able to remove.

Any advice and or suggestions is appreciated.

IMHO, it would be very unlikely that needles would cause the hard starting you describe since the carbs start with the throttles closed and the slides all the way down. The bike starts on the very rich "chocke" system which isn't actually a choke but a big jet that dumps a lot of gas in. It also runs on the pilot circuit since the throttle is closed so both choke and pilot systems are suspect when there's hard starting, the choke is probably not working right.

I agree that the needles would have no impact on it starting, but since I was taking the carbs apart to clean I figured why not change them out and the clip position.

I had the same problem. I was able to carefully drill the head of the screw off, then use a smaller bit to drill the body of the screw out. Just be careful not to strip the threads. I found if I drilled the head off just right, when I went to drill the body out, it just screwed itself through.

Use a left hand drill bit real slow and it should bite the screw
and turn it out.

I don't know what a left handed drill bit is, how is this any different from a normal drill bit?

And rokit, did you use something comparable to a dremmel tool? And you drilled out the center bit? I am more of a visual leaner, do you have any Pictures by any chance.

A left handed drill bit is basically the opposite cutting thread to a normal right facing drill bit, personally ive never tried this method but it looks a lot less faffing about than doing it with the stud extractor, this youtube video is a good visual guide:

Thank's SKK.
I bet he was thinkin I was being a smart a$$

Haha got to admit it does sound like a Tartan Paint kind of thing