OK I'm going to go over a little carb fundamentals, I'll also post up some pictures that you can reference to.
First let me start off and say that setting up the carb the right way is critical, it is a precise part that is delicate and ultimately in the end will dictate how you machine performs.
I have seen so many times after someone has worked on a carb where they left out parts or damaged a part and put things together wrong....the list goes on.
So you need to start and look at the diagram and make sure that all the parts you see on that sheet are there in your carb, remember it was designed to have all those parts installed.
The pilot screw on this carb is "fuel metering" the base setting for a # XXXXX jet is a turn and a half (1 1/2) now since its fuel metering the more you tun it out the more fuel is added at low speed/idle. (mainly idle) as some as you start to give it throttle its off that circuit.
The starter plunger, you can unscrew the brass nut out of the carb body and then slide the plunger out, if you look on the underneath surface you'll see a black rubber seal, make sure that it sealing when its inserted in the carb body, you should see an imprint on the rubber where it was sealing on the carb body, and make sure that you have free play in your starter (choke) cable.
Now when you unscrewed the top cap off to remove the cable/slide out of the carb body I want you to grab the slide with two fingers and then with your other hand see if you can move that needle up and down, remember you told me that was a washer missing, so I will assume that you should have up and down play in that needle, YOU Shouldn't HAVE ANY PLAY THERE ! if you do then that means the needle is bouncing around and not metering your fuel correctly.
Last you need to check your float height that is really critical and needs to set to that spec.
I'm going to let you look at this if you have any questions rely back, I'll be in and out today.
Edited by Kenny O on 5/22/2010 at 4:17 PM EST