Read the can directions for how much! I dont have one in front of me, but you really dont need alot at all for a motorcycle. seafoam is great for oil and gas. You CAN put it in the cylinders too if you choose. Read this on their website:
http://www.seafoamsales.com/motorTuneUpTech.htm Theres alot of info on their site. If you still have a question, they DO answer emails! They have a great staff on hand for helping you use their product.
boat engine and bike engine 2 different things. but, you are correct with filling with product till stalling ... Stabil mixed in a full tank, turn off fuel to carbs, let run till it dies (after running the bike a few miles to make sure the stabil mixes well and is IN the carbs). I have read that putting oil in the cylinders isnt that great of a thing to do on motorcycles for short term storage. i'll see if i can find what i read about that and put it up here. and One is right, too much oil in there you will have fouled plugs. You can buy some Fogging Oil to put in the cylinders and is made specifically for this application.
i would suggest NOT using WD40 in the cylinders. that stuff is water based... and you know what water does. Get yourself some fogging oil or use the Seafoam.