Carb rebuild help

[RoadRacer 831]

I finally got a little time to start going over this 250 SX I picked up a couple of weeks ago. It isn't quite running right so my first project is to rebuild the carb. I've hit a little problem though... I can't seem to get the 2 little screws out of the vacuum piston. I can't think of a good way to describe them, but they screw into the "arm assembly" inside the piston, covering the needle. The screws are number 30 on this diagram. http://www.bikebandit.com/partsbandit/showschematic~dept_id~175522~mscssid~2ECRT21D9V858 L22Q89B5JGLNDH3D1S0.asp

They are phillips head screws but are starting to round out from trying to turn them. There isn't enough clearance to get an impact driver down to it. Any suggestions? I was hoping to take the entire thing apart to clean, but would this part be better left alone?

I'd like to go through the whole trike pretty thouroughly cleaning/painting/repairing/restoring as I go. Has anyone restored one of these that might have some general step by steps of a good way to do this? Maybe even some pics? I've seen some project threads but would like some more detailed tips/instructions as I've never done this before.
Thanks,
Andy

[Huffa]

I know exactly what you are talking about as I almost ran into the same problem but I made darn sure that the screw driver fit perfect, put solid even pressure on them and they came out but I got to tell ya, it was on the verge slipping, I could just feel it. I was lucky.

They should not be philips at all, allens would be much better.

I don't have an answer though as how to get them out. Maybe a shop could get a tool in there to grind the heads away?

I guess you want to put a new needle in then or raise or lower it on the clip?

[twoodward15]

if you can't get them out then take you handy dremey tool ang grind a slot accross the screw for a straight tippis driver and use that, but not until you absolutely can't get them out with the phillips!!!

[RoadRacer 831]

I'd really like to do that, but there isn't enough clearance to get a dremel tool in to cut the head. I guess I can try some more different phillips head screwdrivers, but I don't think they are going to budge.